The Aspect OF RF & EMC Testing in Today’s World · Web viewThe Aspect OF RF & EMC Testing in Today’s World EE1001E: Emerging Technologies in Electrical Engineering 15 November

The Aspect OF RF & EMC Testing in Today’s WorldEE1001E: Emerging Technologies in Electrical Engineering

15 November 20122012-2013 Semester 1

Prepared for A/Professor Mehul Motani

Prepared by Kyaw Soe Hein (A0103612Y)

EE1001E Emerging Technologies In Electrical Engineering

Table of ContentsNo. Contents Pg. No

Abstract …………………………………………………………………………………… 3 – 4

1. Introduction…………………………………………………………………… …………. 5

2 EMC testing……………………………………………………………………………….. 62.1 EMC Requirement and Standard Committees………………………………….…………. 62.2 EMC Technical Knowledge …………………………………………………..................... 7 – 82.3 EMC Tests…………………………………………………………………………………. 8 – 92.3.1 Conducted Emission (CE)…………………………………………………………………. 9 – 102.3.2 Radiated Emission (RE)…………………………………………………………………… 11 – 122.3.3 Other Tests of EMC……………………………………………………………………….. 12

3 Radiated Frequency (RF) Testing…………………………………………………………. 133.1 Overview………………………………………………………………………………….. 133.2 RF Testing Requirement & Regulatory Committees…………………………………….... 143.3 RF Frequency……………………………………………………………………………… 14 – 163.4 RF Tests …………………………………………………………………………………… 16 – 173.4.1 Maximum Output Power…………………………………………………………………... 173.4.2 6dbm Channel Bandwidth (Emission Bandwidth)………………………………………… 183.4.3 Maximum Peak Power Spectrum Density…………………………………………………. 183.4.4 Unwanted Emission into Non-Restricted Bands…………………………………………... 183.4.5 Unwanted Emission into Restricted Bands………………………………………………... 18 – 193.4.6 Band Edge Measurement………………………………………………………………….. 19

4 Economics & Market Value……………………………………………………………….. 20

5 Technology Trends & Technical Challenge of RF & EMC……………………………….. 215.1 Proliferation of Microprocessors…………………………………………………………... 215.2 Higher Operating Frequencies…………………………………………………………….. 225.3 Large Equipment and System……………………………………………………………… 225.4 Health and EM fields………………………………………………………………………. 225.5 Accelerating Product Life cycles…………………………………………………………... 235.6 A Paucity of EMC Engineers and Economy………………………………………………. 235.7 Other Technology Trends associated with EMC & RF…………………………………… 23 – 25

6 Recommendation…………………………………………………………………………. 26

7 Conclusion………………………………………………………………………………… 27

References…………………………………………………………………………………. 28Appendix………………………………………………………………………………....... 29 – 40

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The Aspect of RF & EMC Testing in Today’s World

By Kyaw Soe Hein, 1st Year B.Tech (Electronics), National University of Singapore

Abstract

As far as we are concerned, the electronics products consists of complex modules and RF circuits as well as WLAN and Bluetooth devices are aggressively employed in every days’ life of people which in turn create far more emission and disturbance to the environment than it used to be in the past century.

Therefore, the regulation must come in placed as these devices’ RF signal and electrical disturbance coupled each other, resulting in failure of operation in one another as in airplane malfunctions, electrical hazards , and as well as cancer causing Radiation to Human. Hence, regulation and certification of electronics products come in light of safety issue that is to be committed through RF (Radiated Frequency) & EMC (Electromagnetic Compatibility) testing.

The new Era of Communication began in Europe in 1892 where Germany parliament voted for “Law of Telegraph” and Electrical & Electronics era started as early as 18th Century. By the time, the Corporation the author work for existed as Boiler Inspection Association in Germany. As time goes by, it’s became world-wide known 3rd party certification Organization, TUV SUD GROUP. It developed main business division of testing and certification in RF & EMC field as the usage of electronics equipments and telecommunications devices are increasingly high .Without the certificate of EMC clearance, the electronics products cannot be sold legally.

The history of the testing service will be much less popular as to mention the less abundant use of electronics and RF products in the past. However, excessive RF energy could bring adverse effect on health, thus Standards and regulation come in control so do the testing as well.

Electromagnetic compatibility (EMC) is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects (Electromagnetic interference, or EMI) that such energy may induce.

Radio frequency (RF) is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating current which carry radio signals. RF technology is widely applied in wireless applications and Bluetooth devices.

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http://en.wikipedia.org/wiki/Gigahertz


The various types of testing are available for both RF and EMC control. However, radiated emission, conducted emission, radiated immunity, and conducted immunity for EMC and RF testing as WLAN and Bluetooth tests as well as SARS are important areas.

In order to operate in safe and non-disturbance conditions of electronics products, the measurement and regulations are guided by Standards. Those standards are developed by various standards committee and regulated by respective authorities of the countries globally.

As the consumer electronics companies are racing in competitive markets, the Certification clearance of the products is vital to their product launch. As mentioned, there is respective authority of each country to allow the products to be sold in the market. Therefore, it is critical to carry out testing in advance before the mass production accordingly to which standards the country adopts. E.g. USA adopts FCC. EU adopts EN or CISPR standards.

More Complex electronics devices and much advanced RF technology are applied elsewhere. It is crystal clear to see that from RFID card, car lock, and 4G LTE service to HI-FI player employ RF technology.

Smart Grid and Electrical Car- this upcoming technology will create more complex compatibility problem as the smart grid is power distribution system with electronics devices. Automotive EMC will be also linked with power line EMC as these electrical cars are charged via grid utility. Nuclear Plants- more strict necessary measure of EMC is to be applied in nuclear power plant. Mobile Services- 4GLTE is newly available band and it is expected to develop more bands for mobile or WLAN usage.

As mentioned above, the demands of advanced technology results in updated test method of EMC and RF testing. The standards committee, like FCC and IEEE 802.22, will update new test methods regularly on yearly basis. In addition, the equipments are to be upgraded to match with newly updated standards.

As there will be more complex bandwidth of RF and complicated electrical design as in electric ships and air-craft carrier, the upgrading of equipments to follow up high energy and high frequency is inevitable.

All in all, the testing of EMC and RF has evolved along the way comparatively to the development of human technology. This is to ensure all the existing and upcoming technology bear no harm to society and they all can be integrated into the system which in turn, results in brighter future for electronics.

Nevertheless it is believed that the devices and systems developed will weigh more advantages, by means of EMC and RF testing to regulate its compatibility with the environment. Therefore, EMC and RF testing become an important aspect of our daily life as there are there to protect the society and provide high standards of living for everyone.

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1. Introduction

Dated back to late 20th Century to present 21st Century, one may find the gaining momentum of Electronics Device Usage in every part of our daily life. It is quite astonishing that we are living in the world with electronics devices even though we don’t notice them all, ranging from(POS) Point of Sales System, Hand phones, Digital Camera, Note Books, Energy meter, Digital entertainment system to advanced scientific measurement instruments in the labs. Thus, people enjoy improved efficiency, saving-time, accuracy, better mobility and enhanced joyful entertainment from the electronics products. In some way, it is much more user friendly than analog or mechanical-orientated instruments, as well as cost is dramatically reduced in as they could be produced in high quantity. The recent development of wireless communication system, aircraft aerial system and RFID (Radiated Frequency Identification) technology has huge impact on numerous applications. Strictly speaking, in fact, life is about connections and today, many of those connections are wireless. However, there are few negative impacts of highly applied electronics devices in our society as one may speak of. Nevertheless, the world is at its peak for using electronics devices and it is clear that negative impacts are off-set by efficiency and productivity brought by them if they are properly regulated.

It is undeniable that electronics devices became part of our life and must uphold the usage of electronics devices. However, it is necessary to make certain that these electronics devices are optimized to its functionality without compromising safety hazard to human or within themselves. The device is particularly developed but, if the users are likely to be affected in terms of health hazard, hindering daily operation, and creating of interference to the associated equipments, it is meaningless to use as it pose damages to the society. Ultimately, electronics products must adhere to safety standards and regulations so that we could enjoy using electronics products to its highest possibilities in our everyday lives.

However, in this report, it will be much discussed on how these electronics devices are tested and certified to use by consumers in terms of Electromagnetic Compatibility (EMC) and Radiated Frequency (RF) Testing. Unfortunately, the aspect of safety to human body will be not discussed. It will only be in-depth focus on types of EMC & RF test technically, covering the procedures of the test, current and future trend of these testing. In fact, technical challenge and importance of these testing in our daily life will be revealed. Hopefully, from this report, one may seek the knowledge and importance of Electromagnetic Compatibility (EMC) and Radiated Frequency (RF) Testing as these test maintain and uphold the interoperability within devices and

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reliance of the electronics products in the market. Knowing that EMC & RF testing bring about the satisfaction to the people where quality and safety are of what most concerned.

2. EMC Testing

2.1. EMC Requirement & Standards Committees

Most of the industrialized nations have established Agencies or Regulatory bodies responsible for defining and enforcing EMC standards. Products developers are necessary to go through EMC testing and obtained certifications from regulatory bodies, such as CB, CE, FCC, VCCI, PSE, BSMI, ACA, IC, IDA, “eK” mark to sell their products in the intended region legally. This is a step to make sure products are safe to use and, are not giving interferences to associate or nearby devices. In this process, reliability/performance of the products sold in the region is not compromised.

There are several regulatory bodies all over the world; few of them are named below.

International Electrotechnical Commission (IEC), which has several committees working full-time on EMC issues. These are:

Technical Committee 77 (TC77), working on electromagnetic compatibility between equipment including networks.

Comité International Spécial des Perturbations Radioélectriques (CISPR) or international Special Committee on Radio Interference

International Organization for Standardization (ISO), which publishes standards for the automotive industry.

Comité Européen de Normalisation (CEN) or European Committee for Standardization.

Comité Européen de Normalisation Electrotechniques (CENELEC) or European Committee for Electrotechnical Standardisation.

European Telecommunications Standards Institute (ETSI).

United States:

The Federal Communications Commission (FCC). The Society of Automotive Engineers (SAE).

Britain:

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The British Standards Institution (BSI).

Germany:

The Verband der Elektrotechnik, Elektronik und Informationstechnik (VDE) or Association for Electrical, Electronic and Information Technologies.

2.2. EMC Technical Knowledge

Thoughtfully, it is appropriate to present the brief idea of EMC technically before proceeding to various types of EMC so that one could have much more understanding of technical terms and idea of EMC testing.

By definition, Electromagnetic compatibility (EMC) is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects (Electromagnetic interference, or EMI) that such energy may induce.

In another words, Electromagnetic compatibility (EMC) is the ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbance to anything in that environment.

EMC compliance is important in the sense that the device in a given electromagnetic environment is carried out correct operations without interfering to different equipments which use or respond to same electromagnetic phenomena and avoid any effects against equipment’s operation. Basically, EMC is the control of EMI (Electromagnetic Interference) so that unwanted interoperability issues are prevented.

Furthermore, EMC could be subdivided into different issues as following.

EMI is the radiation emitted and its effects on the victim. Emission is the unwanted generation of electromagnetic energy by some emitter or source. Susceptibility or Immunity is the ability of the receptor or victim equipment to operate

correctly in the presence of electromagnetic disturbances. Susceptibility and immunity are opposites - an equipment which has high susceptibility has low immunity, and vice versa.

Coupling is the mechanisms by which EMI is able to travel from source to victim.

It is important to mention that any electronic devices which use clock signal or oscillator present EMI issue. Those capacitors, resistors and inductors are often source of the EMI as well. Therefore, EMC compliance is not eliminating the EMI issue rather controlling it to its tolerable situation or below specified limit.

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In applications, there is always electromagnetic radiation or else coupling EMI effect in conducted way e.g. Power line. Take Laptop as an example, while you are in the seminar room, there are number of laptops emitting Radiation. However, one should not interfere with another’s operation. Not only by means of radiation, as well as by means of coupling into power line, as supply power line shared among several laptops. Therefore, EMC compliance plays a major role; problems such as LCD flickers and power failure will be prominent if the laptop is not EMC compliance.

To enhance better understanding in technical, the following diagram will serve its purpose.

2.3. EMC Tests

In order to get a certificate and get approval from regulatory bodies, one must go thorough series of tests to be done. Types of tests need to be done are different for different products and depends on which certification they going after. This is according to which region

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Fig 1. EMI: Radiation & Conductive Coupling Mode

Source: Wikipedia

http://en.wikipedia.org/w/index.php?title=File:EMI_coupling_modes.svg&page=1


of the world the products will be imported. This will not be discussed in details here. However, commonly, the devices can be categorized in medical, scientific, industrial, Information Technology Devices, Entertainment systems and automotive products.

Basically, there are mainly two kinds of test methodology for all the system, Emission Test or Immunity test/Susceptibility test. The former is to observe how much interference could a device can give out to the surrounding and the latter is on how much severity a device can sustain its operation to the interference given by the surrounding.

In terms of testing, most of the tests are similar in manners, however different in test methods and test levels of severity. The printer could emit Electromagnetic propagation to its office associated equipments, computers and projectors. Therefore, it is necessary to measure the emission profile of it to check if it is within specified limit. This is called Emission test.

Generally, automotive products require withstanding high level of voltage/ current severity while information technology devices require relatively lesser severity of test. The idea of testing is to simulate the real world impact of EMI on the tested product and observe its respond to the given interference. And this is called Immunity or Susceptibility test.

The common mandatory tests of EMC are listed below.

Conducted Emissions(continuous and discontinuous interference) Radiated Emissions and EMF Power Interference Harmonic current emission Voltage fluctuation / flicker Electrostatic Discharge (ESD) immunity Radiated field Immunity Electrical fast transient / burst immunity Voltage surge immunity Conducted disturbances immunity Power frequency magnetic field / oscillatory waves immunity Voltage dips/ interruptions immunity Harmonics and inter-harmonics immunity Electrical disturbances from Conduction and coupling immunity for vehicals Antenna input immunity(S1) Immunity to induced voltage(S2a) Antenna immunity to RF voltage(S2b) Immunity from radiated fields(S3) Antenna screening effectiveness(S4)

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Among of above mentioned tests, particular tests are most essential to initial R&D developments for the products of ISM (industrial, scientific, and medical) equipments and ITE (information technology equipments). As those products are mainly seen in our everyday life, it is wise to take those tests as examples in this report to present the aspect of EMC testing in Today’s World.

2.3.1 Conducted Emission (CE)

Conducted emission is one of the most important tests regarded by many regulatory agencies. This is due to the unwanted emissions from electronics products using the AC power grid are observed to cause interference with other devices nearby. In turn, these devices induce emissions onto the commercial distribution system and again, couple to a very large distribution of wires. According to antenna theory, the wires system can act as a large antenna system from which these conducted emission can radiate electromagnetic fields which can interfere with other electronic devices. Therefore, it is necessary to take measurement of conducted emission to check if the emission is within the limited level

set by regulatory bodies.

The setup of conducted emission test should also be briefly described to have an overview as the procedure, frequency range and limits are important to understand. The frequency range for the measurement of conducted emission is 150 kHz to 30 MHz for most commercial products. Few products (Industrial / Military specification) start with as low as 30 Hz. The Impedance stabilization network (LISN) will be used to make the CE testing as it eliminates the noise from the power grid and the emission measured is purely from the equipment itself i.e. filtering effect. Thus, LISN will be placed between equipment under test (plugged into one end of LISN) and the

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Fig2. AC power Line Sharing

Source: Google

(http://www.google.com.sg/imgres?q=power+line+diagram&um=1&hl=en&tbm=isch&tbnid=Fa09nHKaWHsD0M:&imgrefurl=http://www.amazon.com/ZyXEL-Powerline-HomePlug-Wall-plug-Adapter/dp/B000ZD2OIS&docid=Iiv59OdQ2IHlDM&imgurl=http://g-ecx.images-amazon.com/images/G/01/electronics/detail-page/PowerlineDiagram500.jpg&w=500&h=36

Fig2. CE Test Set-up


commercial power system (the other end of LISN). The sample data is attached in Appendix.

2.3.2 Radiated Emission (RE)

Radiated emission is regulated nearly worldwide. This is because unwanted emissions from electronic products can and do cause interference with nearby devices. In the case of radiated emissions, the EUTs (Equipment Under Test) are normally treated as point sources and the radiated transmission path is through air. If the radiated emissions are strong enough, it has the potential to cause interference with a nearby source. A good example of interference would be the static interference experienced by the car AM radio when stopping at a light under overhead power lines. The field being radiated from the power lines is picked up by the car antenna and is mixed with the received radio signal. The radio filters are not strong enough to filter out the power line noise and it is heard as static. Therefore, it is necessary to measure emission profile of the device and check against with the limit to determine it is appropriate to use in office and home environment (Class B) or strictly to be used in industrial environment (Class A). In another words, RE test is required to describe the nature of spurious or intended signals generated by the device.

The Radiated Emission (RE) test is arguably the most import test as solving the Radiated Emission (RE) issue would favor the result of the rest of the tests. As mentioned earlier, immunity/susceptibility test is also required to have EMC compliance. Imagine one device is emitting weak electromagnetic propagation; the impact on the other device would be also weak. Therefore, if the devices in the whole region of particular place displayed low Radiated Emission, it is unnecessary to check the devices’ immunity in that particular region. In other words, no emission issue means there will be any immunity issue considerably. This is applied for FCC (US) regulatory certification. However, the rest of the region like EUROPE, Japan and Singapore would require going for immunity testing.

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Fig2. CE Test Set-up


Therefore, it is vital to fix the radiated emissions problems as it can potentially help in passing the immunity tests later in the test sequence also. The EUT (Equipment Under Test) needs to redesigned in a way of mitigating the emission. This will save the product developer

time and money as they can cancel the immunity tests, if they desire, and focus on fixing the radiated emissions failures, true for FCC, United States of America.

The fundamental setup of Radiated Emission (RE) is standardized by the regulatory agencies although there are minor differences. The EUT (Equipment Under Test) is tested on an OATS (Open Area Test Site) facility or in an anechoic chamber. Fig 3. This is to create a noise-free environment where EUT will be exercised and measuring the noise from EUT only. In details, the EUT is placed on a turntable and any emission from the EUT will be measured with an antenna placed at a 3 or 10 m distance while antenna is varying its height 1-4m. The turntable is moving 360° to measure noises outsource from all the direction. During the test, EUT is exercising its intended operations in applications with I/O ports

loaded. The interested frequency range will be mostly from 30MHz-1GHz, 1GHz-6GHz, 6GHz-25GHz or as high as 400GHz, according to which kind of products going for certification. The sample data is attached in Appendix.

2.3.3 Other Tests of EMC

As described in above topics, one would have been seen the important tests of EMC and appreciate the EMC compliance as they are presented with real world issue related to EMC/EMI

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Fig 3. 10m Anechoic Chamber

Source: TDK RF Solution

(http://www.ramayes.com/TDK_EMC_Compliance_Anechoic_Chamber.htm)


problems. However, the other tests such as Power Interference, Harmonics Current Emission, voltage fluctuation/ flicker are also necessary to go through as it could determine the performance of the device when it is connected to the commercial power grid and observe the behavior of its respond. Electrostatic Discharge (ESD) Immunity test is as well important as it simulates the static discharge of human body when it is touched to the enclosure or user interface of the device. The weather conditions, temperature and humidity, could create electrostatic discharge effect on the device, therefore within specified environmental conditions, the device should still be performing as normal. Radiated field immunity is to observe the performance of the device when it is subjected to EMI from the surrounding emission. Electrical Fast Transient, voltage surge immunity, and conducted disturbances are to check if the device can sustain its operating fashion when the disturbances in AC power grid is couple from other devices shared power utility or when lightning is struck on its communication cables. This is as well important in a sense that some communications are essential in daily life, police force communication, aerial control center, and military operations. Having EMC compliance can be assure its operability in any situation. Therefore, major destructive or life threatening events are well handled by help of electronics devices, provided they are certified.

3. Radiated Frequency (RF) Testing

3.1. Overview

Noticeably, there have been dramatically increased usages of wireless and RF technology in daily life of everyone. It brings up productivity and ease of intended operations for human beings. People tend to communicate wirelessly and the trend is growing day by day. Mainly, it is concerned with wireless long range or nearby field communication system. From the voice heard from the mobile phone to the images you see on your Television Set, the data is being transmitted using radio frequency or ‘RF’ technology. Internet & emails are also served by wireless network by services providers. One might probably tune to AM or FM stations to enjoy music of its choice. RFID (Radio-frequency-identification is widely use in Bus-passenger-fee paying system, entry and exit of the place, and even, it can be implanted in the body for locating the people wherever on the earth. This technology is critically useful for miners who have a high chance of trapping inside mine. They could just tag the RFID chip along with them, therefore rescuers can easily evacuate them in case of life and dead situation happens. Emergency services communications (police, fire, ambulance) is also supported by RF technology. Moreover, exchange of pictures or data by Bluetooth is also significant prove of RF technology in aspect of RF technology in the world. Therefore, it is necessary to step up in a way that the electronics devices using RF technology must go for RF testing in addition to EMC testing. In the process, the RF devices are kept at its optimum

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performance for people while safety to human and interference to other devices is being uncompromised. As you can seen in Fig.4, the radio communications in the community is crowed the electromagnetic spectrum, therefore RF testing can help them organized and prevent interference between incumbent frequencies.

3.2 RF Testing Requirement & Regulatory Committees

As a matter of fact, RF testing is the part of telecoms testing. In most of the industrialized countries, like USA, CANADA, JAPAN, and Singapore, the electronics devices which consist of RF transmitter / receiver module must go through RF testing so that the products can be launched to market. There are several regulatory bodies for different Regions. Below is the list of most popular regulatory bodies in the world.

United States of America: Federal Communication Commission (FCC)

United Kingdom: Office of Communication (Ofcom)

Canada: Industrial Canada (IC)

Singapore: Infocomm Development Authority of Singapore (IDA)

South Korea: Ministry of Communications and Information (KCC)

Japan: Ministry of Internal Affairs and Communications (MIC)

Europe Region: Mostly accept certification by European Telecommunications Standards Institute (ETSI)

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Fig 4. Radio Communications in the community

Source: EMF Explained Series

(http://www.emfexplained.info/?ID=25186)


Test methods or procedures are different, and as well as, number of tests required to get certification are also not the same. Therefore, products developers are required to go through RF testing according to which region their products will be exported. However, almost all of them are standardized in their requirements so that if you bring your hand phone or wireless router from your hometown in Asia to America, there should not be any interference created between your device and those in America. In fact, that’s the whole idea of RF testing.

3.3 RF Frequency

It would be appropriate to present basics knowledge of RF before proceeding to specific RF test. Basically, Radiated Frequency is the radio wave or electromagnetic propagation from a source. It present in electromagnetic spectrum and naturally, they are generated by lightning or by astronomical objects. Artificially created RF waves are used for fixed or mobile radio communication, broadcasting, radar and other navigation systems, communication satellites, computer networks and innumerable other applications. They could be spread out in whole spectrum, ranging from as low as 30 kHz to 300GHz. Therefore, they could create interference to each other and thus, it is necessary to organize them in groups. Most of the RF devices are operated in 2.4GHz band or increasingly occupying 5GHz band, differing on the type of modulations, bandwidth and ease of applications.

Generally, the 2.4GHz band is over-crowded as it is license free band for any applications. The cordless phone, Bluetooth devices, microwave oven, video devices and Wi-Fi networks operate in the 2.4GHz. This is one of the reason the Wi-Fi manufacture started to operate in 5GHz band which is relatively noise-free than 2.4GHz band. However, the regulatory body set certain requirement to operate in those bands. As mentioned above, the wireless communication is highly applied in most of the places; Electromagnetic interference (EMI) is inevitable problem. In details, EMI is defined as a disturbance effect in electrical or electronics devices due to either electromagnetic induction or electromagnetic radiation emitted from an external source. Disturbance, in turn, degrade or limit the performance of the victim devices. The daily EMI situation can be best described in Fig 5, as laptops, wireless mouse, wireless thermostat, printers, PDA, internet video streaming and even LED light emitting are EMI transmitters as well as victims of it.

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3.4 RF Tests

In terms of presenting RF testing in details, choosing Wi-Fi testing as an example would be much clearer to reveal the idea of overall RF testing as it focus on spectrum sharing, peak power allowance for carrier signal, and Spurious signals measurement for the entire license free 2.4GHz band. Take an example of Hi-Fi entertainment system that is required to obtain FCC certification. The system includes Wi-Fi Tx/Rx module for air play mode from iPhone, iPad, and mobile phone. The antenna gain and no. of available antennas is provided. The module would be tested according to FCC Part 15.247 (DSSS-Digital Modulated Devices). The most important area of RF testing to discuss here is Radio/Wireless tests although it may extend up to Bluetooth protocol and profile conformance tests and Bluetooth interoperability test. However, the latter tests are more focused on functionality, interoperability and doesn’t matter that much for spectrum sharing policy.

In this section, it would be fruitful to the reader to have general idea of how a Wi-Fi product is tested in certified test lab. Example would be Wi-Fi technology device going for FCC

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Fig.5 EMI in daily life.

Source: Google

(http://www.brainpickings.org/index.php/tag/technology/page/68/)


certification. It will be tested according to Guidance for Performing Compliance Measurements on Digital Transmission Systems (DTS) Operating under 15.247. This guidance is applicable only to Digital Transmission System (DTS) devices operating in the 902-928MHz, 2400-2483.5MHz and/or 5725-5850 bands under 15.247 of the FCC rules (Title 47 of the Code of Federal Regulations). However, the below mentioned guide is used for reference only, mainly for general knowledge. Readers are advised to contact Accredited Agency or Regulatory Body if extensive knowledge is required.

The set up of the Wi-Fi testing could be as simple as using only one Spectrum analyzer which can support up to 26.5G, in some cases up to 40G for Industrial Canada standard. Basically, antenna of the Transmitter/Receiver module is connected to RF input port of the Spectrum analyzer. It is more concentrated on conducted measurement. The radiated measurement is almost the same as in EMC Radiated Emission although there are some additional tests. Below is the list of basics tests of RF:

Maximum Output Power 6dbm Channel bandwidth (Emission Bandwidth) Maximum Peak Power Spectrum Density Unwanted Emissions in Non-Restricted Bands Unwanted Emissions in Restricted Bands Band Edge Measurement

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Operating Channels of WLan


The operating channels of Wi-Fi, depending on the developers, have to sub-divide into Low, Mid and High Channels for testing. Most of the cases, developers use Channel 1 to Channel 11.

In this case, Channel 1 is “low”, Channel 6 is “Mid” and Channel 11 is “high”. And, the EUT must transmit continuously with duty cycle more than 98%.

3.4.1 Maximum Output Power

First of all, the maximum output power of the DTS devices is limited to 1W (30dbm). This is to control the interference created by transmitter signal. If the measured output power is above 1W, this module can affect performance of other devices in the same channel. Therefore, it is necessary to check all Low, Mid and High Channel with different Modulation technique and baud rates like 1Mbps, 2Mbps,3Mbps,…9Mbps,18Mbps, 36Mbps, and 54 Mbps. This measurement can be done using power meter, checking overall power out of the transmitting signal.

3.4.2 6dbm Channel Bandwidth (Emission Bandwidth)

It is important to have the information on the channel bandwidth of the signal. This is necessary as to check the signal profile. Any deformation or abnormal noises associated with transmitting signal can be caught here and rectified for better performance. This will be tested for Low, Mid and High Channel with different Modulation technique and baud rates as well. The sample plots are attached in Appendix.

3.4.3 Maximum Peak Power Spectrum Density

Maximum peak power density test will concentrate on the detailed measurement of power of transmitting signal with reference to its emission band width. Unlike maximum output power, it is zoomed into the individual operating channel with lower Resolution Bandwidth. Therefore, it is thoroughly measured and the limit is up to 6dbm set by FCC. It is to regulate the power density of every device operating between 2.4GHz-2.4835GHz, license free band. The

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achievements will consequence in safe operating of devices using this free band. This will be tested for Low, Mid and High Channel with different Modulation technique and baud rates. The sample plots are attached in Appendix.

3.4.4 Unwanted Emission in Non-Restricted Band

Unwanted emission in Non-Restricted Band test is to check if there are any noises or interference created by transmitting signal in license free band. This will covered the entire frequency range, 30MHz -25GHz. The limit is 20dbm below its carrier frequency peak. The interference phenomenon can occur outside of license free band, where other devices are operating due to the concentration of power in transmitting signal. Therefore, it is required to check the entire band with respect to Low, Mid and High Channel with different Modulation technique and baud rates of Wi-Fi operating channels. The sample plots are attached in Appendix.

3.4.5 Unwanted Emission in Restricted Band

Most importantly, unwanted emission in Restricted Band is not desired by any users of frequency spectrum. The limit is changing according to value set by FCC, according to its frequency ranges. This is to regulate and organized the devices in control, limiting interferences on each other. It will cover much wider form 9 kHz to 25 GHz. Low, Mid and High Channel with different Modulation technique and baud rates of Wi-Fi operating channels are to be tested. The sample plots are attached in Appendix.

3.4.6 Band Edge Measurement

Last of all, the band edge measurement is to assure the border of 2.4GHz license free band is noise-clean. As the name tells, it is checked at the edge of the operating channels, in this case, tested for Low and High Channels with different Modulation technique and baud rates. The check point is at 2.39GHz at lower channel and 2.4835 at upper channel as described in the above information on Non-overlapping channels for WLAN. From 2.4GHz-2.39GHz and 2.4835GHz-2.5GHz, the noise should not be higher than the level, 20dbm below the peak of its carrier frequency. This will in turn grantee the performance of the devices in free band, without introducing interferences. The sample plots are attached in Appendix.

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.

4. Economics and Market Value

EMC & RF certification is very important in an aspect of economics, in terms of launching the products ahead of competitor companies. If the product has been developed for 1 year, then finally go through EMC & RF testing, however resulting in failure. It could miss the targeted launch date and thereafter, it could result in dramatic low sale as customers are already in touch with competitors’ products and decided to buy the same technology. Today’s is considered rat racing in economy. Most exciting event could be seen in Hand phone maker companies like Apple, Samsung, LG, Motorola, Nokia, and HTC. If one could step ahead of competitors by 1 week, it will make huge impact on business sale.

Therefore, EMC and RF certification affects the capabilities in business strategy, program management, and organizational design to haste the launch of products and time to market. Outcomes such as achieving market share goals, decrease time-to-market, risky recall of

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products, managing sophisticated regional requirement are fulfilled if EMC & RF testing is focused while product is in developing state. Thus, EMC & RF solution companies are also making huge fortune by assisting products developers in testing and certification. Moreover, third party certification bodies companies accredited by regulatory bodies can grant various certifications by providing test facilities and technical knowledge and they are also making business around the globe. The approved list of Third Party Certification Bodies (TCB) can be found on the basics of countries can be found on the website of standards.org @ http://www.standards.org/certification_bodies/.

5. Technology Trends & Technical Challenges of RF & EMC

The future trend of electronics development in-separately co-exists with the technical challenges of RF & EMC. The growing demand of current technology will result in the more challenging requirement for RF & EMC testing. The electromagnetic compatibility issues will become complex for new technology devices with reference to current ones. RF testing will be much more intensive and details as the growing wireless communications will populate the license-free bands and license required bands. The most important of all, the increasing density of microprocessors in homes, business, factories, and transportation vehicles will induce technical challenges for EMC & RF testing.

In general, it requires more sophisticate equipments and updated knowledge. The regulatory bodies have to standardize the requirements and conduct field testing worldwide by applying new technology driven devices. This will incur significant efforts and money.

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The future technology trends and technical challenges can be concluded in

1) Proliferation of Processors2) Higher Operating Frequency3) Large equipment and systems4) Health and Electromagnetic field 5) Accelerating Product Life cycles6) Paucity of EMC engineers and Economy

5.1 Proliferation of Processors

Today’s electrical appliances, computer, information technology devices, communications devices and household machines are smarter by incorporating microprocessors to achieve better performance. Therefore, compatibility problems will be raised among these devices as in the future there will be many more emitters and victims of EMC field. For fixed microprocessors, EMC could be solved easily by using current EMC solving technique. However, it is expected that fixed microprocessors will be replaced by mobile transmitters as the demand of controlling and communicating the devices remotely is increasing. Therefore, it is high possibility of transmitters in nearly every piece of electronics with Bluetooth and Wi-Fi technology.

Apparently, the devices using Bluetooth (Frequency Hopping Spread Spectrum) and Wi-Fi (Direct Sequence Spread Spectrum) need to be regulated by RF testing. These devices should operate properly when it is exposed to the incident radio signal. However, the challenge is that it is unclear whether other devices not designed for wireless technology will operate in the vicinity of EMI interference. Thus, processors for different equipments operating in different frequencies need to be standardized and regulated. This will become the technical challenge of EMC & RF Standards regulators.

5.2 Higher operating Frequency

Another challenge introduced will be the future trend of continual increase in operating frequency of the electronics products coming into the market. Take a look at the frequency spectrum, hand phone services provider use above 1 GHz, Bluetooth and Wi-Fi at 2.4 GHz, satellite communications at near 10 GHz and automobile radar systems at above 40 GHz. Higher operating frequencies have smaller wavelengths and are able to penetrate the victim equipments more easily than lower frequencies. In the process, it will disturb the environment and the development of new microprocessors operating at clock speed of 1 GHz will again introduce direct-interference in the operation of electronics systems. Hence, EMC & RF measurements will become vital and important for the whole world.

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5.3 Large Equipment & Systems

The current EMC standardization is a success in producing test methods to evaluate the acceptability of equipment and small systems built by manufacturers. However, developing standard methods for evaluating immunity of large equipment or systems can be more much complicated. In fact, size is a problematic factor as test facilities to host large systems are expensive to build and immunity testing performed at open-area test sites can be difficult to perform. There is a way of disassemble the entire system and test the individual equipments. However, this is unpractical or hard to determine the actual emission of the systems and immunity to EMI field while it is operating in real applications.

5.4 Health and Electromagnetic Field

In terms of health and safety, the alarm has also sounded. Since 19th Century, people have concerned on health hazards imposed by Radio Towers. Therefore, it is not strange that increased use of microprocessors driven electronics devices and wireless technology is widely seen as a threat to people. Therefore, future EMC & RF testing should include measurement of EMI for human exposure and its effect on health. Besides, one of the main concerns is possibility of electromagnetic disturbances causing electronics systems to malfunction and thus, present a safety risk at work place and office environment. For example, a cell phone 900MHz signal in a factory could cause an industrial robot to behave so as to injure a worker. Another area of interest is the reliability of emergency communication system. The higher use of wireless technology can induce interference to radio system of police, ambulances or military. Therefore, it is necessary to increase a scope of EMC and RF testing in near future to cover all these areas.

5.5 Accelerating Product Life Cycles

In the EMC standardization process, it is considered that the rapidity of technological change and short span of time for products development is a continual problem to achieve EMC in every region of the world. This technology flux grant EMC standardization bodies very little time to evaluate the impact of new technologies on maintaining of EMC balance. Additionally, companies developing new electronic products and technologies do not normally participate in the standardization process, the likelihood of interference between devices increases.

5.6 Paucity of EMC Engineer and Economy

In addition to structural problems in the EMC & RF standardization process, the availability of EMC experts in all areas from product development to standards writing is the

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another problematic area. It is seen that fewer engineers are graduating with the credentials necessary to deal with EMC challenges. It is mainly due to the economic direction of the world. The rewards in the industry today are mainly going to business management, sales and computer experts. Many engineers in the EMC field do not receive support from their management for work they do. Another main problem is that IEC and its national committees which develop EMC & RF standardization needs the sale of standards to keep its organization going. And there are nearly around 60% of world’s electronics products having fake certificates and they are distributed in the market by illegal ways such as on-line shopping.

5.7 Other Technology Trends associated with EMC & RF

It would be much more complete if EMC in smart grid, EMC and RFI for nuclear power plant, and overview of Cognitive Radio (CR) applications are presented here. Smart Grid is increasingly seen as a means to facilitate climate friendly renewable energy sources and to enable efficient use of electricity. The modern electrical network, Smart Grid is a large “System of Systems”, it can monitors, protects, and automatically optimize the operation of its interconnected elements- from the central and distributed generator through the high-voltage network and distribution system, to industrial users and building automation systems, to energy storage installations and to end-use consumers and their thermostats, electric vehicles, appliances, and other household devices. This complex arrangement of Smart Grid results in dramatic use of electronics devices in the system. Therefore, electromagnetic compliance is vital for realization of a robust Smart Grid. Moreover, smart energy meters will be installed at the end user part and transmit the data to control & distribution center wirelessly. Therefore, RF testing for those meters using wireless or Ethernet technology plays a role as well.

.

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Electromagnetic compatibility and Radio-Frequency-Interference is the major safety in Nuclear Power Plant. Spontaneous valve closures at the Niagara Mohawk Nine Mile Point #2 nuclear

25

Fig. 6 Smart Grid Concept

Source: Carbon Metrics

(http://www.carbonmetrics.eu/Smart-Grids.php)


power plant were due to interference generated by workers' wireless handsets. Despite the tremendous emphasis on safety and security that is placed on the design and construction of all nuclear power plants, the relatively weak emissions from common wireless handsets resulted in a major malfunction. Therefore, those countries having Nuclear Power Plant set the safety standard and take action to abide the standard by force. For United States, U.S. Nuclear Regulatory Commission (NRC) plays a major role for EMC & RFI standard for nuclear plants. Regulatory Guide 1.180(RG-1.180) : 2003 Guideline for evaluating electromagnetic & radio-frequency interference (EMI & RFI) in safety-related instrumentation and control systems” is place in order. This regulatory guide endorses design, installation, and testing practices acceptable to the NRC staff for addressing the effects of EMI/RFI and power surges on safety-related instrumentation and control systems. Another leading enforcement body is from KOREA. It apply Regulatory Guide 1.180 (RG-1.180): 2003 for emissions (EMI) and immunity (EMS) as well.

The promising trend in wireless applications is the emerging of Cognitive Radio Technology. This technology is a consequence of new spectrum policy and regulatory domains. The CR technology can support a variety of emerging applications, ranging from Smart Grid, public safety and broadband cellular, to medical applications. The CR technology (primarily from a dynamic spectrum access perspective) would bring benefits and also, some challenges for EMC & RF testing regulatory bodies in terms of standardization. By definition, A cognitive radio is a transceiver which automatically detects available channels in wireless spectrum and accordingly changes its transmission or reception parameters so more wireless communications may run concurrently in a given spectrum band at a place. This process is also known as dynamic spectrum management. A cognitive radio, as defined by the researchers at Virginia Polytechnic Institute and State University, is "a software defined radio with a cognitive engine brain".

The FCC (Federal Communications and Communications) of US and Electronics Communications Committee (ECC) of European Post and Telecommunications in Europe had begun working on cognitive radio in the cellular Network, Public Safety Network, and Medical Body Network and so on, in a way that, pre-occupied channels are not disturbed by upcoming CR technology driven devices..

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6. Recommendations

In this section, it will be presented on how EMC and RF technology challenges can be answered. Many of the approaches have been sought out and some are even beginning to start off practicing. As a matter of fact, these challenges can be solved if the standardization bodies can co-ordinate with one another and relevant practices are followed by product developing companies. First of all, consistency of standards is most important of all. One major strategy is to intensify and focus EMC standards within IEC. In the same way for RF standards, it should

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Fig. 7 Cognitive Radio Concept: Showing CR technology as New Path.

Source: Google


focus standardizing with U.S, Europe and Asia. The main goal is to develop a single set of emission and basic EMC and RF test standards that can be practiced by all manufacturers.

Secondly, it is recommended to EMC engineers and scientists to evaluate emerging technologies. As the world is feeding on technological advances, there will be several issues coming up in terms of EMC and RF. Therefore, anticipation of new technologies, including reviewing the popular and scientific literature should be formulated. This could be done under the organizing of IEC’s, FCC, ETSI and several regulatory bodies such as meetings or seminars to uncover potential conflicts of operation. It is also important that companies pursuing the development of innovative technologies should be encouraged to contact standards bodies for advice on how to minimize interference with other systems that might be incurred by using upcoming products.

Moreover, the promising area for handling challenges will be “Standardized Tests for High Frequencies”, those above 1 GHz. As new products will intensively employ high frequencies in future, it is necessary to prepare ahead. Thus, test labs around the world can be responsive to the rapid development of new products. Additionally, the complex functional problems caused by electromagnetic disturbances can be deferred by the close monitor of Regulatory Bodies and attention of EMC experts. As well as, random inspections on electronics devices in the market and take action against to those responsible could help to sustain the quality and safety of electronics products.

7. Conclusion

With many thoughts, it would be very satisfying if one could gain knowledge and outlook of RF and EMC testing by reading “The Aspect of RF & EMC Testing in Today’s World”. As mentioned earlier in this report, the world is heavily relying on electronic devices. This trend will not stand still and continual growth will be observed in the future as well. Therefore, it is very important that upcoming technology will not crowd-out the existing technology in terms of spectrum sharing and most importantly, electromagnetic compliance should be balance between

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them. Safety and health are major concerns in every aspect of life. In another way, EMC & RF testing assure “the safety and health” is met for the mankind. One could possibly imagine the world with no standardization of EMC and RF. It could be a total mess; devices will be interfered by each other. It will compromise safety of electrical shocks or performance degradation, and communication failure in times of emergency. With the help of EMC and RF regulations, the world is enjoying the benefits from electronics products in terms of efficiency, time-saving, productivity and opening ways for much more advanced technology for the human kind.

It is true that the electromagnetic environment will be crowded and as well as, more and more interference will be exposed. However, positively thinking, the EMC and RF experts will find a way to organize our spectrum and minimize EMI issues on electronics products. Most importantly, the considerable and constant effort should be exerted to sustain the EMC/EMI compliance of todays for the future. Personally, it is believed that if there is a co-ordination of Standard Regulatory Bodies, Test Labs and industrial involvement, people could enjoy high quality and better performance of the electronics products. And, with many hopes, there will always be EMC and RF compliance for everyone.

References

TUV SUD PSB Internal EMC & RF knowledge data base

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EMI COMPLIANCE TESTING AND MITIGATION FOR TEST LABORATORY ENGINEERS By CHIP FLEURY, Resource And Business Development Manager

Electromagnetic Compatibility (EMC), Part 1: General, Section 2: Methodology for the

Achievement of Functional Safety of Electrical and Electronic Equipment with Regard to Electromagnetic Phenomena, Draft IEC 61000-1-2 (Geneva: International Electro-technical Commission, 1999).

Electromagnetic Compatibility (EMC), Part 1: General, Section 2: Methodology for the Achievement of Functional Safety of Electrical and Electronic Equipment with Regard to Electromagnetic Phenomena, Draft IEC 61000-1-2 (Geneva: International Electro-technical Commission, 1999).

TÜV SÜD Group: Presentation on Nuclear Safety guide for EMC and RFI, presented by

Dr. Deng Junhong IEEE Communications Magazine . March 2011 Frequency Sharing Policy of FCC:

http://transition.fcc.gov/oet/spectrum/table/fcctable.pdf

http://www.elliottlabs.com/services_emc_why.htm http://en.wikipedia.org/wiki/Electromagnetic_compatibility http://en.wikipedia.org/wiki/List_of_telecommunications_regulatory_bodies http://www.ce-mag.com/archive/01/Spring/Radasky.html www.interferencetechnology.com/power-quality-and-emc-in-smart-grid/ Latest DTS measurement Guide by FCC

http://apps.fcc.gov/kdb/GetAttachment.html?id=WM5vEQ95Ya78a3hVcrdEGg%3D%3D

Appendix

Disclaimer: All the data and plots provided here are solely the references of RF & EMC measurements. They do not represent any products already in market or products that are in developmental stage. The only purpose is to provide extensive knowledge of RF & EMC testing to the Readers. All the data are original efforts by the author of this report.

Conducted Emission

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http://www.interferencetechnology.com/power-quality-and-emc-in-smart-grid/

http://www.ce-mag.com/archive/01/Spring/Radasky.html

http://en.wikipedia.org/wiki/List_of_telecommunications_regulatory_bodies

http://en.wikipedia.org/wiki/Electromagnetic_compatibility

http://www.elliottlabs.com/services_emc_why.htm

http://transition.fcc.gov/oet/spectrum/table/fcctable.pdf


0.15 30.000.50 1.00 5.00 10.000

110

102030405060708090100

Frequency

Level

[MHz]

[dB(µV)]

EN55022 Class B Standard- Information Technology Equipment

Frequency [MHz]

Line Phase

Reading QP

[dB(µV)]

Reading AV

[dB(µV)]

Factor [dB]

Level QP

[dB(µV)]

Level AV

[dB(µV)]

Limit QP

[dB(µV)]

Limit AV

[dB(µV)]

Margin QP [dB]

Margin AV [dB]

0.17805 Live 38.0 21.6 11.2 49.2 32.8 64.6 54.6 15.4 21.80.16105 Live 32.3 7.2 11.1 43.4 18.3 65.4 55.4 22.0 37.112.7278 Live 31.0 24.1 11.0 42.0 35.1 60.0 50.0 18.0 14.90.63258 Live 25.2 15.2 11.2 36.4 26.4 56.0 46.0 19.6 19.6

0.23463Neutra

l 36.0 26.9 9.7 45.7 36.6 62.3 52.3 16.6 15.7

7.4634Neutra

l 26.2.0 19.1 9.8 36.0 28.9 60.0 50.0 24.0 21.1

0.29523Neutra

l 29.7.0 23.0 9.7 39.4 32.7 60.4 50.4 21.0 17.7

Note: Positive (+) Margin means the measurement is met the acceptable criteria of the standard.

Radiated Emission

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30.000 1000.000250.000 500.000 750.0000

100

10

20

30

40

50

60

70

80

90

Frequency

Level

[MHz]

[dB(µV/m)]

FCC Part 15 Class B- Information Technology Equipment

Frequency [MHz] (P)

Reading [dB(µV)

]

Factor [dB(1/m)

]

Level PK [dB(µV/m)

]

Limit QP [dB(µV/m)

]Margin QP [dB]

Height [cm]

Angle [°]

30.0000 Vertical 36.3 -5.1 31.2 40.0 8.8 100 335100.6800 Vertical 49.5 -15.4 34.1 43.5 9.4 98 8122.2760 Horizontal 51.9 -14.4 37.5 43.5 6.0 201 359132.0930 Vertical 52.6 -14.3 38.3 43.5 5.2 100 93204.7360 Vertical 50.1 -16.3 33.8 43.5 9.7 100 25491.3820 Vertical 41.7 -7.1 34.6 46.0 11.4 98 317752.5040 Horizontal 37.1 -3.9 33.2 46.0 12.8 100 186799.6240 Vertical 41.5 -3.3 38.2 46.0 7.8 100 259964.5430 Vertical 41.1 -1.2 39.9 54.0 14.1 98 109976.3230 Vertical 41.2 -1.0 40.2 54.0 13.8 98 74

Note: Positive margin (+) value represents the measurement is met the acceptable criteria of the standard.

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6dbm Bandwidth Measurement (Emission Bandwidth)

Channel 01 ( Low Channel)

Channel 06 ( Mid Channel)

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Channel 11 (High Frequency)

Maximum Peak Power Spectrum Density Measurement

Channel 01 (Low Frequency)

34


Channel 06 (Mid Channel)

Channel 11 (High Channel)

35


Unwanted Emission in Non-Restricted Band

36


Unwanted Emission in Restricted Band

37


38


39


40


41


Band Edge Measurement

42

Documents

The Aspect OF RF & EMC Testing in Today’s World · Web viewThe Aspect OF RF & EMC Testing in Today’s World EE1001E: Emerging Technologies in Electrical Engineering 15 November