ee433c_Microwave Engineering I_100119.pdf

8/7/2019 ee433c_Microwave Engineering I_100119.pdf

1/17

Microwave Engineering I

Course code EE433C

Date 2010-01-19

Time 09:00 14:00

Course Coordinator Claes Beckman and Jos Chilo

/0739823453

_____________________________________________

Exam information_____________________________________________

Material Allowed - Ruler, compass, pencil and calcul

Grading The examination consists of 8 quesnumber of points per question is sh

together with the problem text. The

points.

GradeA minimum 28.8 p

B minimum 25.6 p

C minimum 22.4 p

D minimum 19.2 p

E minimum 16.0 po


2/17

Problem 1A KA-band radar has a peak output power of 500W, a pulse repetition frequency o

duration time of 15s. The radar is equipped with an antenna with a gain of 30dBi density of the radiated power is increased with 30dB in the main direction of the anWhat is the minimum safety distance the radar according to the The Swedish RadiAuthority's General Advice on the Limitation of Exposure of the General Public to

(4p)

Problem 2A generator is connected to a transmission line as shown below. Find the voltage as

transmission line. Plot the magnitude of this voltage for 0 z . (4p)

Problem 3Consider a length of Teflon-filled copper K-band rectangular waveguide.

a) Find the cutoff frequencies of the first five propagating modes. (2p)b) If the operating frequency is 18 GHz, find the attenuation due to dielectric andProblem 4A two-port network is driven at both ports such that the port voltages and currents h

(Z0 = 50 ):

008.0904

904.0020

22

11

IV

IV

Determine the input impedance seen at each port, and find the incident and reflecte(4p)

Problem 5

A load impedance 4030 jZL is to be matched to a 50 line using a single

Find two solutions using short-circuited stubs and Smith Chart. (4p)

Problem 6A circular cavity resonator with d = 2a is to be designed to resonate at 5 GHz in th

If the cavity is made from copper and is Polyethylene-filled, find its dimensions an

Problem 7Design a single-section coupled line coupler with a coupling of 19.1 dB, a system icenter frequency of 8 GHz. If the coupler is to be made in stripline (edge- coupled)b = 0.32 cm, find the necessary strip widths and separation. (4p)


3/17

SSI FS 2002:3 Unofficia

The Swedish Radiation Protection Authority's General Advice

on the Limitation of Exposure of the General Public to ElectroFields;

issued on October 28th

2002.

The Swedish Radiation Protection Authority gives the following genera

1. Application

1.1 The purpose of these general advice is to protect members of thfrom acute harmful effects from exposure to electromagnetic fields in

range 0 Hz 300 GHz.

The general advice are based on recommendations from the

European Union1. They are intended to serve as guidelines for the applic

6 of the Radiation Protection Act (1988:220).

1.2 In the general advice basic restrictions as well as reference levels ar

The basic restrictions ensure that electric and magnetic effects within the human body do not disturb functions of the central nervo

cause harmful heating of an organ or a tissue. The reference levels ar

are measurable outside the human body. They are derived from the b

and ensure that the basic restrictions are not exceeded.

If measured levels exceed the reference levels, this does not neces

the basic restrictions are exceeded. In such cases the basic restrictio

these general advice should apply.

The basic restrictions are in accordance with international recom

down at levels of about 2 percent of the levels where negative he

scientificly established.

1.3 These general advice are applicable in areas where members of th

may be situated in such periods of time giving meaning to the advice.


4/17

2. Basic restrictions

2.1 Electromagnetic fields of a kind that imply that the basic restrictioTable 1 are exceeded should not occur at any point where members

public may be situated according to clause 1.3.

Table 1 Basic restrictions for electric, magnetic and electromagnetic fie

(0 H z 300 GHz)

Frequency rangeMagneticflux

density

Currentdensity

(effectivevalue)

SAR(Wholebod

y

(meanvalue)

LocalSAR

(headandtrunk)

LocalSAR

(armsandlegs)

Powerdensity

S

(mT) (mA/m2)

(W/kg) W/kg) (W/kg) (W/m2)

0 Hz> 0 Hz - 1 Hz

1 Hz - 4 Hz

4 Hz - 1 kHz

1 kHz - 100 kHz

100 kHz - 10 MHz

10 MHz - 10 GHz10 GHz - 300 GHz

40-

-

-

-

-

-

-

-8

8/f

2

f/500

f/500

-

-

--

-

-

-

0.08

0.08

-

--

-

-

-

2

2

-

--

-

-

-

4

4

-

--

-

-

-

-

-

10

f is the frequency expressed in Hz.

Current density is the mean value over 1 cm2

perpendicular to the

direction of the current.

All SAR-values (Specific Absorption Rate) refer to the mean value

in a 6 minute period of time.

Local SAR should be calculated as the mean value over a mass of 10

g contiguous tissue.


5/17

Table 2 Reference levels for exposure of the general public (0 Hz 300

Frequency range E-fields H-fields B-fields

Equivalepower defor a plan

(V/m) (A/m) (T) Seq (W

0 Hz - 1 Hz

> 1 Hz - 8 Hz

8 Hz - 25 Hz

25 Hz - 800 Hz

800 Hz - 3 kHz

-

10000

10000

2.5105/f

2.5105/f

3.2104

3.2104/f

2

4000/f

4000/f

5

4104

4104/f

2

5000/f

5000/f

6.25

-

-

-

-

-

3 kHz - 150 kHz

150 kHz - 1 MHz

1 MHz - 10 MHz

10 MHz - 400 MHz *

400 MHz - 2 GHz

87

87

8.7104/f1/2

28

1.375 f1/2

1000

5

7.3105/f

7.3105/f

0.073

0.0037 f1/2

1000

6.25

9.2105/f

9.2105/f

0.092

0.0046 f1/2

1000

-

-

-

2

f/(2

2 GHz - 300 GHz 61 0.16 0.20 1

* In the frequency range 10 MHz 110 MHz an additional reference l

45 mA for induced current in each leg or arm should apply.

f is the frequency expressed in Hz.

In the frequency range 100 kHz to 10 GHz, Seq, E2, H

2and B

2refere

mean value over a 6 minutes' period of time.

At frequencies higher than 10 GHz, Seq, E2, H

2and B

2are calculated

mean values over a period of time that is 68/(109 f)1.05minutes, wh

expressed in Hz.

The mean values for E-fields, H-fields and B-fields are calculated

square roots of the mean values, during the considered period of time

squares of the quantities respectively.


6/17

restriction should apply so that the absorbed energy per pulse doe

millijoule per kilogram evaluated as the mean value over 10 grams cont

4.3 Concerning peak values of E-fields, H-fields and B-fields r

effective value (RMS) according to Table 2 multiplied by a factor accor

should apply.

Table 3 Factors for the calculation of peak values

Frequency range Factor

< 100 kHz100 kHz - 10 MHz

210 where = (0.665 log (f/105) + 0.176) *

10 MHz - 300 GHz 32

* f is expressed in Hz

5. Simultaneous exposure to a variety of frequenciesFor exposure to fields consisting of a variety of frequencies simu

possibility that the fields may add up to give a certain biologic effect

into account. Thus thermal effects in the body and other effects shoul

separately.

Basic restrictions

5.1 Concerning electric stimulation in the frequency range 1 Hz - 10 M

current densities are summed up according to the equation

10MHz

i = 1 Hz

JiJLi

1

5.2 At thermal effects (frequencies higher than 100 kHz) SAR and pow

summed up according to the equation

10 GHz

i = 100kHz

SARiSARL

+

300 GHz

i > 10 GHz

SiSL

1


7/17

Reference levels

5.3 To prevent effects by electric stimulation at frequencies up to 1

following equations apply:

1MHz

i = 1 Hz

EiELi

+

10 MHz

i > 1 MHz

Eia

1

and

150 kHz

k = 1 Hz

HkHLk

+

10MHz

k > 150 kHz

Hkb

1

where

Ei is the E-field at frequency i,

ELi is the reference level according to Table 2 for an E-field at frequency

Hk is the H-field at frequency k,

HLkis the reference level according to Table 2 for an H-field at frequenc

a = 87 V/m andb = 5 A/m.

5.4 For thermal effects (frequencies higher than 100 kHz) the two follo

apply:

1 MHz

i = 100 kHz

Ei2

c2 +

300 GHz

i > 1 MHz

Ei2

ELi2 1

and

150 kHz

k = 100 kHz

Hk2

d

2

+

300 GHz

k > 150 kHz

Hk2

HLk

2 1

whereEi is the E-field at frequency i,

ELi is the reference level according to Table 2 for an E-field at frequency

Hk is the H-field at frequency k,

HLkis the reference level according to Table 2 for an H-field at frequenc

c = 8.7 104 /f V/m andd 7 3 10

5/ f A/ I b th f i d i H


8/17


9/17


10/17


11/17


12/17


13/17


14/17


15/17


16/17


17/17

Documents

ee433c_Microwave Engineering I_100119.pdf