Applications of Computer Modeling in Electromagnetic Compatibility (EMC) Tests (Part1)

ESE – Andrew Rusek

P9. Example 3: Two Cell Phone Antennas and Two Receiving Objects

Receiving Objects

Cell Phone Antennas

Grounded Object

Suspended Object

Two Cell Phone Antennas, Field Directivity for 0.8 GHz, The Same Phases

Two Cell Phone AntennasField Directivity Changes for 1.5 GHz, Opposite Phases Two Cell Phone Antennas, Field Directivity Changes

for 1.5 GHz, The Same Phases

P10. Two Cell Phone Antennas, Field Directivity for 0.8 GHz, Opposite Phases

P11. Opposite Phases The Same Phases

Grounded ObjectGrounded Object

Summary:

EMC measurements are performed to protect electrical equipment from potential interfering signals caused by uncontrolled and intentional sources. The presentation includes examples of simulated basic Controller Area Network (CAN) experiments, including conducted and radiated emissions. Simulated CAN immunity tests are also shown. In addition, results of computer simulations of EM fields generated by GHz frequency basic structures are presented. Necessity of testing GHz devices is due to high speeds of clocks of computers and signals of new cell phones. At GHz frequencies the distribution of EM fields emitted by Devices Under Test (DUT) become non-uniform. Computer simulation of experiments can be the way to reduce time required to find the DUT field directivity.

P7. Example 2: Simulated EMC Radiation Test for Three Radiating Objects

Test AntennaRadiating Objects

Field Directivity Tests for 0.6 GHz, 1.0 GHz, and 1.5 GHz

P8. Field Pattern of Three Radiating Objects (0.6 GHz) All Sources in Phase

Field Pattern of Three Radiating Objects (1.0 GHz) All Sources in Phase

Field Pattern of Three Radiating Objects (1.5 GHz) All Sources in Phase

Current Distribution in Various Segments of Test Antenna Versus Frequency. All Sources in Phase

changes of current magnitude show effects of directivity variations with frequency

Applications of Computer Modeling in Electromagnetic Compatibility (EMC) Tests (Part2)

ESE – Andrew Rusek

P1. New Electromagnetic Interference Issues Investigated at OU:

GHz frequency range interference and radiating device directivity (necessity of introduction of new EMC standards and measurement methods to recognize device directivity) Simulations helpful to detect peaks of radiation, and prepare experimentation and training

Cell phone and other wireless device interference into sensitive medical and automotive systems (Hospitals, Automobiles, etc)

GPS and other navigation instrumentation EMC problems PRESENTED: Examples of Modeling

Example 1: CISPR (EMC Standards) based conducted and radiated emissions tests;

Immunity tests. Controller Area Network (CAN) transceivers are tested (Research completed in cooperation with DaimlerChrysler)

Example 2: Simulated GHz range EMC radiation test for three radiating objects to observe field directivity effects

Example 3: Example 3: Two Cell Phone Antennas and Two Receiving Objects

P2. Example 1: Transceiver Modeling

Common-Mode Filter Structure

Mid-Layer Model of CAN TransceiverModel of CAN Transceiver with External Components

Internal Transmitter Model

Internal Receiver Model

P3.

Antenna Model for CISPR 25 Radiated Emission TestsDeveloped by Mr. W. Hall, DaimlerChrysler

CAN TransceiverTransmitting Pulses CAN Receiver

Receiving Pulses

Twisted Pair Cable

P4. Conducted and Radiated Emission Test

Simulated Conducted Emissions

Simulated Radiated Emissions

Measured Conducted Emissions

Measured Conducted EmissionsMax. freq = 5 MHz

MHz

Measured Conducted EmissionsMax. freq. = 50 MHz

P5. P6. Simulated Immunity Tests

Interrupted Communication

Interfering Signals

Interference Generator

OK signals

Transmitted Signal

Received Signal