1. By Professor Syed Idris Syed Hassan Sch of Elect. & Electron Eng Engineering Campus USM Nibong Tebal 14300 SPS Penang Microwave Circuit Design

2. Introduction 10 weeks lecture + 4 weeks ADS simulation Assessments :8 tests + 2 ADS assignments + 1 final examination Class : 9.00- 10.30 lecture 10.30-11.00 rest (tea break) 11.00-12.30 lecture 12.30- 1.00 test

3. Dates 06/04/02 Morning 20/04/02 Morning 27/04/02 Morning 04/05/02 Morning 11/05/02 Morning 18/05/02 Morning 25/05/02 Morning 08/06/02 Morning 15/06/02 Morning 22/06/02 Morning 29/06/02 morning 06/07/02 Morning 20/07/02 Morning 27/07/02 Morning

4. Syllabus Transmission lines Network parameters Matching techniques Power dividers and combiners Diode circuits Microwave amplifiers Oscillators Filters design Applications Miscellaneous

5. References David M Pozar,Microwave Engineering- 2 nd Ed., John Wiley, 1998 E.H.Fooks & R.A.Zakarevicius, Microwave Engineering using microstrip circuits, Prentice Hall,1989. G. D. Vendelin, A.M.Pavio &U.L.Rohde, Microwave circuit design-using linear and Nonlinear Techniques, John Wiley, 1990. W.H.Hayward, Introduction to Radio Frequency Design, Prentice Hall, 1982.

6. Transmission Line

7. Equivalent Circuit RRLL C G Lossy line Lossless line

8. Analysis From Kirchoff Voltage Law Kirchoff current law (a) (b)

9. Analysis Let’s V=V o e j  t, I = I o e j  t Therefore then a b Differentiate with respect to z

10. Analysis The solution of V and I can be written in the form of where Let say at z=0, V=V L, I=I L and Z=Z L Therefore and e f c d

11. Analysis Solve simultaneous equations ( e ) and (f ) Inserting in equations ( c) and (d) we have

12. Analysis But and Then, we have and * **

13. Analysis Or further reduce or For lossless transmission line,  = j  since 

14. Analysis Standing Wave Ratio (SWR) node antinode Ae -  z Be  z Reflection coefficient Voltage and current in term of reflection coefficient or

15. Analysis For loss-less transmission line  = j  By substituting in * and **,voltage and current amplitude are Voltage at maximum and minimum points are and Therefore For purely resistive load g h

16. Analysis Other related equations From equations (g) and (h), we can find the max and min points Maximum Minimum

17. Important Transmission line equations ZoZo ZLZL Z in

18. Various forms of Transmission Lines

19. Parallel wire cable Where a = radius of conductor d = separation between conductors

20. Coaxial cable Where a = radius of inner conductor b = radius of outer conductor c = 3 x 10 8 m/s a b

21. Micro strip w hehe rr t t=thickness of conductor Substrate Conducted strip Ground

22. Characteristic impedance of Microstrip line Where w=width of strip h=height and t=thickness

23. Microstrip width For A>1.52 For A<1.52

24. Simple Calculation Approximation only

25. Microstrip components Capacitance Inductance Short/Open stub Open stub Transformer Resonator

26. Capacitance ZoZo ZoZo Z oc For

27. Inductance ZoZo ZoZo Z oL For

28. Short Stub ZoZo Z ZoZo ZoZo ZLZL

29. Open stub ZoZo Z ZoZo ZoZo ZLZL

30. Quarter-wave transformer ZoZo ZoZo ZTZT  Z mx/min ZLZL x  in radian At maximum point

31. Quarter-wave transformer  in radian at minimum point

32. Resonator Circular microstrip disk Circular ring Short-circuited  /2 lossy line Open-circuited /2 lossy line Short-circuited /4 lossy line

33. Circular disk/ring a feeding a * These components usually use for resonators

34. Short-circuited  /2 lossy line  n /2 Z in ZoZo  where = series RLC resonant cct

35. Open-circuited /2 lossy line  n /2 Z in ZoZo  = parallel RLC resonant cct where

36. Short-circuited /4 lossy line  /4 Z in ZoZo  = parallel RLC resonant cct where

37. Rectangular waveguide a b Cut-off frequency of TE or TM mode Conductor attenuation for TE 10

38. Example Given that a= 2.286cm, b=1.016cm and  x   S/m. What are the mode and attenuation for 10GHz? Using this equation to calculate cutoff frequency of each mode

39. Calculation TE 10 a=2.286mm, b=1.016mm, m=1 and n=0,thus we have Similarly we can calculate for other modes

40. Example TE 10 TE 20 TE 01 TE 11 6.562GHz13.123GHz14.764GHz16.156GHz Frequency 10Ghz is propagating in TE 10. mode since this frequency is below the 13.123GHz (TE 20 ) and above 6.561GHz (TE 10 )

41. continue or

42. Evanescent mode Mode that propagates below cutoff frequency of a wave guide is called evanescent mode Wave propagation constant is Where k c is referred to cutoff frequency,  is referred to propagation in waveguide and  is in space  j  = attenuation  =phase constant When f 0 < f c, But Since no propagation then The wave guide become attenuator

43. Cylindrical waveguide a TE mode Dominant mode is TE 11

44. continue a TM mode TM 01 is preferable for long haul transmission

45. Example Find the cutoff wavelength of the first four modes of a circular waveguide of radius 1cm Refer to tables TE modes TM modes 1 st mode 2 nd mode 3 rd &4 th modes

46. Calculation 1 st mode Pnm= 1.841, TE 11 2 nd mode Pnm= 2.405, TM 01 1 st mode Pnm= 3.832, TE 01 and TM 11

47. Stripline w b

48. Continue On the other hand we can calculate the width of stripline for a given characteristic impedance

49. Continue Where t =thickness of the strip