sietkece.comsietkece.com/wp-content/uploads/2016/08… · Web view · 2017-01-23The biggest advantage of the trapatt diode over the impatt diode is it's [ ] (a) Lower noise (b)

SIDDHARTH GROUP OF INSTITUTIONS :: PUTTURSiddharth Nagar, Narayanavanam Road – 517583

QUESTION BANK (OBJECTIVE)

Subject with Code : MWE (13A04603) Course & Branch: B.Tech - ECE Year & Sem: III-B.Tech & II-Sem Regulation: R13

Unit-1

Waveguides and Resonators

1. Microwave frequency range is ------ [ ]

(a) 1 Khz-100 Khz (b)1 Mhz-100 Mhz (c) 1 Ghz-1000 Ghz (d) None

2. --- is a Object detection System that uses microwaves [ ]

(a) Microwave oven (b) Transmitter (c) Radar (d) Satellite

3. ---- is an electronically controlled home appliance used for cooking [ ]

(a)Radar (b) Microwave oven (c) Satellite (d) None

4. In --- Wave Both A & B electric and magnetic fields are purely transverse [

]

(a) TE (b) TM (c) TEM (d) None

5. --- is hollow metallic tube used for Transmitting EM waves [ ]

(a) Strip line (b) Micro strip line (c) Waveguide(d) None

6. Minimum possible mode for TM modes is ----- [ ]

(a)TM00 (b) TM01 (c) TM10 (d) TM11

7. Minimum possible mode for TE modes is ---- [ ]

(a) TE00 (b) TE01 (c) TE10 (d) b & c

8. Waveguide acts as ---- filter [ ]

(a) Low pass (b) Band reject (c) Band pass (d) High pass

9. Speed of EM wave in free space is ------ [ ]

(a) 3 x 1010m/s (b) 3 x 1012cm/s (c) 3 x 1010cm/s (d) None

10. The mode having highest cut-off wavelength is called as ---- [ ]

(a) Dominant mode (b) Degenerate mode (c) Both A & B (d) None

11. The mode having lowest cut-off frequency is called as ---- [ ]

(a) Dominant mode (b) Degenerate mode (c) Both A & B (d) None

12. ---- is dominant mode for TM waves in rectangular waveguide [ ]

(a) TM00 (b) TM01 (c) TM11 (d) TM11

13. --- is dominant mode for TE waves when a > b in rectangular waveguide [ ]

(a) TE00 (b) TE10 (c) TE01 (d) TE11

14. The distance travelled by the wave in order to undergo a phase shift of 3600 called as--[ ]

(a) Phase velocity (b) group velocity (c) guide wavelength (d) None

15. -----is the relation between λg and β [ ]

(a) β =2πλg (b) β =πλg (c) β =2π/λg (d) None

16. --- is relation between Vp and β [ ]

(a) Vp = w/ β (b) Vp = w β (c) Vp = β / w (d) None

17. --- is relation between Vg and β [ ]

(a) Vg = dw/ dβ (b) Vg = w/β (c) Vg = wβ (d) None

18. Product of Phase velocity and group velocity is --- [ ]

(a) Square of speed of light (b) Speed of light (c) Speed of sound (d) None

19. Frequency range of voice signal is ------ [ ]

(a) 0 – 4 Khz (b) 20 – 20 Khz (c) 1 Mhz – 10 Mhz (d) None

20. Frequency range of audio signal is ----- [ ]

(a) 0 – 4 Khz (b) 20 – 20 Khz (c) 1 Mhz – 10 Mhz (d) None

21. --- theorem used for calculating power transmission and power losses [ ]

(a)Pointing (b) Thevenin’s (c) Norton’s (d) None

22. Rectangular waveguide supports ---- waves [ ]

(a) TE (b) TM (c)TEM (d) TE & TM

23. ----- is a metallic enclose formed by shorting two ends of waveguide [ ]

(a) Cavity Resonator (b) Amplifier (c) Tank circuit (d) None

24. In cavity resonators, distance between shorting end plates is multiple of --- [ ]

(a) λg/2 (b) λg (c) λg/4 (d) λg/3

25. ---- is a measure of frequency selectivity of resonant or anti resonant circuit [ ]

(a)Q factor (b) Amplifier (c) Oscillator (d) None

26. ------ is the relation between Q, fr & BW [ ]

(a)BW= fr x Q (b) BW= fr / Q (c) BW= fr x Q2 (d) None

27. If f = 600 Mhz then λ= ---- [ ]

(a) 0.5 m (b) 1 m (c) 2 m (d) None

28. Cavity resonators used in ----- [ ]

(a)Oscillator (b) filter (c) Both A & B (d) None

29. At low frequencies cavity resonator works similar to ----- [ ]

(a) Low pass (b) High pass (c) Tank circuit (d) None

30. If λ = 1m then f= ---- [ ]

(a) 300 Mhz (b) 3 x 108 hz (c) Both A & B (d) None

31. In Microwave we take the elements as [ ]

(a) Lumped circuit elements (b) Distributed circuit elements

(c) Both A & B (d) None

32. For handling large microwave power, the best medium is [ ]

(a) Coaxial line (b) Rectangular waveguide

(c) Strip line (d) Circular waveguide

33. Which of the following noise becomes important at microwave frequencies [ ]

(a) Shot noise (b) Flicker noise

(c) Thermal noise (d) Transit time noise

34. The phenomenon of microwave signals following the curvature of earth is known as [ ]

(a) Faraday effect (b) Ducting (c) Wave tilt (d) Troposcatter

35. Microwave frequency range extends from [ ]

(a) 3 MHz to 30 MHz (b) 30 MHz to 300 MHz

(c) 300 MHz to 3000 MHz (d) 500 MHz to 30000 MHz

36. Due to curvature of earth, microwave repeaters are placed at a distance of about [ ]

(a) 10 Km (b) 50 Km (c) 150 Km (d) 250 Km

37. At microwave frequencies the size of the antenna becomes [ ]

(a) Very large (b) Large (c) Small (d) Very Small

38. Short term fading in microwave communication links can be overcome by [ ]

(a) Increasing the transmitted power (b) Changing the antenna

(c) Changing the modulation scheme (d) Diversity reception and transmission

39. ---- is a process used for monitoring and controlling the vehicle. [ ]

(a) Radar (b) Modulation (c) Navigation (d) Microwave Oven

40. RADAR is a Object detection System that uses ---- [ ]

(a) Long Waves (b) Medium Waves (c) Short Waves (d) Satellite

SHORT QUESTIONS

1. Define Microwave and list the applications of microwave. [L1][CO.1][2M]

2. Describe IEEE microwave bands. [L2][CO.1][2M]

3. List the advantages of microwaves. [L1][CO.1][2M]

4. Define Wave guide and guide wave length. [L1][CO.1][2M]

5. Expalin cut-off wave length for RWG. [L2][CO.1][2M]

6. Define dominant mode with respect to a waveguide. Mention dominant mode for Rectangular and

circular waveguides. [L1][CO.1][2M]

7. If the broader dimension of a rectangular waveguide is 2.2cms, what is the cut-off Frequency and

wavelength for dominant mode? [L4][CO.1][2M]

8. Is a waveguide equivalent to a high pass filter or a low pass filter? Explain [L2][CO.1][2M]

9. In the notation TEmn and TMmn what do m and n represent? [L1][CO.1][2M]

10. What is cavity resonator? List the types of cavity resonators. [L1][CO.1][2M]

11. What is the two boundary conditions must be met in a waveguide for a Wave to travel down the guide?

[L1][CO.1][2M]

12. Define group velocity? [L2][CO.1][2M]

13. What is Waveguide? What are advantages Waveguide over coaxial cable? [L1][CO.1][2M]

14. What are the major bands available in microwave frequencies? [L1][CO.1][2M]

15. Calculate the cut-off frequency of the following modes in a square waveguide 4 cm × 4 cm TE10,

TM11. [L3][CO.1][2M]

16. Show that TM01 and TM10 modes in a rectangular waveguide do not exist. [L1][CO.1][2M]

17. Define wave impedance. [L1][CO.1][2M]

18. Write short notes on “Cavity resonators and its applications”. [L1,L6][CO.1][2M]

19. Define TEM, TE, and TM modes? [L1][CO.1][2M]

20. A rectangular wave guide has a = 4 cm, b = 3 cm as its sectional dimensions. Find all the modes which

will propagate at 500 MHz. [L5][CO.1][2M]

ESSAY QUESTIONS

1 (a) Discuss how the microwave spectrum is categorized into different bands. [L2][CO.1][4M]

(b) What is the need of microwave frequency? Explain different applications of Microwaves.

[L1,L2][CO.1][6M]

2 (a) Explain the wave impedance of a rectangular waveguide and derive the expression for the wave

impedance of TE and TM modes. [L][CO.1][6M]

(b) Calculate the cut-off frequency of the following modes in a square waveguide 4 cm × 4 cm TE10,

TM11 and TE22. [L4][CO.1][4M]

3 (a) Show that a waveguide works like a high pass filter. [L1][CO.1][5M]

(b) A waveguide having dimensions a = 5 cm, b = 2 cm. The signal applied to waveguide

is10GHz. Determine the modes that are propagating in the waveguide. [L4][CO.1][5M]

4 Derive the expressions for

the field components due to

TE waves in rectangular

wave guide. [L4][CO.1]

[10M]

5 Explain following terms (a) Guide wavelength (b) Phase Velocity (c) Group Velocity.[L2][CO.1][10M]

6 (a) Show that TM01 and TM10 modes in a rectangular waveguide do not exist. [L1][CO.1][4M]

(b) For a wave guide having cross section 3cm × 2cm, compute the cut-off frequency in the TE01

mode. Also, calculate the phase velocity and guide wavelength at a frequency equal to 50% above the

cut-off frequency. [L4][CO.1][6M]

7 (a) Why TEM modes are not possible in hollow rectangular waveguide? Prove it[L3][CO.1][6M]

(b) When dominant mode propagated in air filled circular waveguide diameter is 4 cms.

Find cut-off wavelength, cut-off frequency and guide wavelength. [L4][CO.1][4M]

8 (a) Define Cavity

Resonator. Draw

Diagrams of

Rectangular &

circular cavity

Resonators. [L1]

[CO.1][4M]

(b) Derive the equation for resonant frequency in circular cavity resonator. [L4][CO.1][6M]

9 (a) Derive the equation for Resonant frequency in rectangular cavity resonator. [L4][CO.1][5M]

(b) Calculate resonant frequency of rectangular cavity filled with dielectric with € r=4 and having

dimensions a=5cm b=4cm and d=15cm. [L4][CO.1][5M]

10 (a) Discuss in detail about Q factor of cavity Resonator. [L1][CO.1][4M]

(b) A wave guide operating in TE10 mode has dimensions a = 2.26 cm and b = 1 cm. The measured

guide wave length is 4 cm. Find

i. Cut off frequency of the propagating mode

ii. The frequency of operation

iii. Maximum frequency of propagation in this mode. [L4][CO.1][6M]




Unit-2

Waveguide Components1. ---- used for producing field intensities in the waveguide [ ]

(a) Probe (b) loop (c) Both A & B (d) None

2. Probe used for setting ---- field in the waveguide [ ]

(a) Electric (b) Magnetic (c) Both A & B (d) None

3. loop used for setting ---- field in the waveguide [ ]

(a) Electric (b) Magnetic (c) Both A & B (d) None

4. For Impedance matching we use ----- [ ]

(a) Windows (b) Posts (c) Screw (d) All

5. When h > λg/4 post behaves like ------ [ ]

(a) Capacitevely (b) Pure resistor (c) Inductively (d) None

6. When h < λg/4 Screw behaves like ------ [ ]

(a) Capacitevely (b) Pure resistor (c) Inductively (d) None

7. ---- used for reducing power of the signal [ ]

(a) Windows (b) Posts (c) Screw (d) Attenuator

8. In Flap attenuator, resistive card inserted completely in waveguide attenuation is - [ ]

(a) Minimum (b) Half (c) Maximum (d) None

9. In Vane type attenuator ,when vane at center attenuation is ----- [ ]

10. Minimum (b) Half (c) Maximum (d) None

11. Rotary vane attenuator provides ---- attenuation [ ]

(a) Fixed (b) Variable (c) Half (d) None

12. In dielectric slab phase shifter, when slab placed inside completely phase shift is - [ ]

(a) Minimum (b) Maximum (c) Zero (d) None

13. H-plane junction also called as ---- junction [ ]

(a) Parallel (b) Series (c) Both A & B (d) None

14. E-plane junction also called as ---- junction [ ]

(a) Parallel (b) Series (c) Both A & B (d) None

15. Combination of E-plane & H-plane Tee called as ----- [ ]

(a) Magic Tee (b) Hybrid Tee (c) E-H Plane Tee (d) All

16. Directional coupler is ----- port network [ ]

(a) Two (b) Three (c) Four (d) Five

17. - used for sampling small amount of microwave power used for measurement purpose [ ]

(a) Gyrator (b) Isolator (c) Circulator (d) None

18. Coupling loop placed along ---- dimensions of the waveguide [ ]

(a) Narrow (b) Broader (c) Both A & B (d) None

19. ---- used for measuring incident power [ ]

(a) Directional coupler (b) Gyrator (c) Isolator (d) Circulator

20. ----- Is the ratio of incident power to forward power [ ]

(a) Coupling factor (b) Directivity (c) Isolation (d) None

21. --- is the ratio of forward power to back power [ ]

(a) Coupling facto (b) Directivity (c) Isolation (d) None

21. Ferrites resistivity is ----- times greater than metal [ ]

(a) 1012 (b) 1014 (c) 1016 (d) None

22. Gyrator provides ---- phase shift from port 1 to port 2 [ ]

(a)00 (b) 1800 (c) 900 (d) None

23. Gyrator provides ---- phase shift from port 2 to port 1 [ ]

(a)00 (b) 1800 (c) 900 (d) None

24. A magic-Tee is nothing but [ ]

(a) A modification of E-plane tee (b) A modification of H-plane tee

(c) A combination of E-Plane and H-Plane (d) Two E-plane tees connected in parallel

25. For some application circular waveguide may be preferred over rectangular because [ ]

(a) The smaller cross section needed at any frequency (b) Lower attenuation

(c) Freedom from spurious modes (d) Rotation of polarization

26. Indicate which of the following cannot be followed by the word waveguide [ ]

(a) Elliptical (b) Flexible (c) Coaxial (d) Ridged

21. ---- is a compound composed of MeO.Fe2O3 [

]

(a) Ferrites (b) FET (c) Diode (d) Transistor

22. Ferrites exhibits ----- property [

]

(a) Non-Reciprocal (b) Reciprocal (c) Modulation (d)None

27. In order to reduce cross sectional dimensions, the waveguide to use is [ ]

(a) Circular (b) Ridged (c) Rectangular (d) Flexible

28. In a directional coupler [ ]

(a) I = C+D (b) C=I+D (c) D=I+C (d) I=CD

29. The waveguide tuning component, which is not easily adjustable, is [ ]

(a) Screw (b) Iris (c) Stub (d) Plunger

30. A frequency at which microwave ovens operate is [ ]

(a) 50 μHz (b) 2.45 GHz (c) 3.3 GHz (d) 4.5 GHz

31. Aircraft surveillance radars mostly operate in [ ]

(a) C band (b) S band (c) L band (d) X band

32. Which of the following materials are generally preferred for waveguides? [ ]

(a) Cast iron and steel (b) Nonmetallic solids including plastic

(c) High carbon steel and vanadium steel (d) Brass and aluminum

33. A microwave component which is used to interconnect two sections of waveguide is the[ ]

(a) T section (b) Curved section (c) Choke joint (d) Tapered wedge

34. Brass is an alloy of [ ]

(a) Copper and Zinc (b) Copper and Iron (c) Copper and Aluminum (d) Copper and Tin

35. The range of frequencies in the X-band is ---- [ ]

(a)1-2 Ghz (b) 2-4 Ghz (c) 4-8 Ghz (d) 8-12 Ghz

36. The range of frequencies in the Ku-band is ---- [ ]

(a)1-2 Ghz (b) 2-4 Ghz (c) 26-40 Ghz (d) 100-120 Ghz

37. Resonant Iris acts as ----- filter [ ]

(a) Low pass (b) High pass (c) Band pass (d) Band reject

38. The following Tee is used in front end of the micro wave receiver [ ]

(a)H-Tee (b) E-Tee (c) Magic Tee (d) None

SHORT QUESTIONS

1. What is attenuator and mention different attenuator? [L1][CO.2][2M]

2. Define directivity and coupling factor of a directional coupler. [L1][CO.2][2M]

3. What are the properties of ideal directional coupler? [L1][CO.2][2M]

4. Define isolator and what is the use? [L1][CO.2][2M]

5. What is Faraday rotation and list the ferrite devices. [L1][CO.2]

[2M]

6. What is a circulator? And write applications of circulators. [L1,L3][CO.2]

[2M]

7. What is scattering matrix? [L2][CO.2][2M]

8. Write about S matrix for magic tee and directional coupler. [L1][CO.2]

[2M]

9. What is magic tee? And write applications of magic tee. [L1,L3][CO.2][2M]

10. Explain Tee junction with two examples [L2][CO.2][2M]

11. Write a brief not on micro-strip lines. [L1][CO.2][2M]

12. Define magic tee with figure? [L2][CO.2][2M]

13. Sketch a 4 port Hybrid junction. Justify that it is basically a 3 dB directional coupler.

[L1][CO.2][2M]

14. Why the S-parameters are used in microwaves? [L2][CO.2][2M]

15. Write the properties of [S] matrix. [L1][CO.2][2M]

16. Define tee junction Name some uses of waveguide tees. [L1][CO.2][2M]

17. Give a note on directional couplers Name some uses of waveguide twists. [L2][CO.2][2M]

18. Define directivity of directional coupler Mention the different types of directional couplers.

. [L1][CO.2][2M]

19. Write the characteristics of a three port tee junction. [L1][CO.2][2M]

20. What is H-plane and E-plane Tee? [L1][CO.2][2M]

ESSAY QUESTIONS

1 (a) Explain the coupling mechanism of waveguide. [L2][CO.2][4M]

(b) Explain the following (i) Waveguide windows (ii) Screws [L2][CO.2][6M]

2 Explain the following (a) precision Variable attenuator (b) rotary vane attenuator. [L2][CO.2][10M]

3 Explain following terms (a)E-plane Tee (b) H-plane Tee (c) Magic Tee [L2][CO.2][10M]

4 (a) Draw a typical directional coupler and define directivity and coupling coefficient.[L1][CO.2][5M]

(b) An 20db directional coupler gives 3 dbm in output power through coupled port. If the Isolation

specified as 55 dB, find the power available at the Isolated Port. [L4][CO.2][5M]

5 What is the principle of phase shifter? Draw the diagram of dielectric phase shifter and discuss the

working mechanism. [L1,L4][CO.2][10M]

6 Explain following terms (a) Gyrator (b) Isolator [L2][CO.2][10M]

7 (a) What is meant by normalized voltage and normalized current with respect to the microwave circuit

concept. Draw a neat sketch of a Magic Tee and obtain its S matrix. [L2,L4][CO.2][6M]

(b) List and Explain two applications of Magic Tee. [L6][CO.2][4M]

8 (a) Derive the S-matrix for E-plane junction. [L4][CO.2][6M]

(b) Explain the principle of Ferrite phase shifter. [L2][CO.2][4M]

9 (a) Derive the S-matrix for Magic Tee junction. [L4][CO.2][5M]

(b) A 20 dB coupler has a directivity of 30 dB. Calculate the value of isolation. [L4][CO.2][5M]

10 (a) Derive the S-matrix for directional coupler. [L4][CO.2][5M]

(b) Using the properties of scattering matrix of a lossless, reciprocal microwave junction, prove that for

a four port network if all the four ports are matched, the device shall be a directional coupler. .

. [L5][CO.2][5M]




Unit-3

Linear Beam Tubes1. If frequency increases ,the inductive reactance will----- [ ]

(a) Decreases (b) Increases (c) Constant (d) None

2. At high frequencies the Ip is-----with grid voltage [ ]

(a) Out of phase (b) Inphase (c) Both A & B (d) None

3. The use of proper shielding of tubes minimizes -----losses. [ ]

(a) Copper losses (b) Radiation Losses (c) Both A & B (d) None

4. The efficiency of two cavity klystron amplifier is ----- [ ]

(a) 25% (b) 58% (c) 90% (d) 46%

5. The working principle of Klystron amplifier is -----modulation [ ]

(a) Frequency (b) Amplitude (c) Velocity (d) None

6. Basically reflex klystron is a ----- [ ]

(a) Amplifier (b) Oscillator (c) Phase shifter (d) None

7. The multi cavity klystron amp can be used for improve----- [ ]

(a) Gain (b) Frequency (c) Current (d) None

8. ------- is the variable frequency oscillator [ ]

(a) Two cavity klystron amplifier (b) TWT (c) Reflex klystron (d) None

9. In Reflex klystron the optimum transit time T= ----- [ ]

(a) n+3/4 (b) n-3/4 (c) n+1/4 (d) None

10. If electron is subjected to +max of RF signal, its velocity ----- [ ]

(a) Increases (b) Decreases (c) Constant (d) None

11. TWT is ----- band amplifier [ ]

(a) Broad (b) Narrow (c) Both A & B (d) None

12. In TWT the RF field is ----- [ ]

(a) Stationary (b) Moving (c) Both A & B (d) None

13. One of the reasons why vacuum tubes eventually fail at microwave frequencies is that their[ ]

(a) Noise figure increases (b) Transit time becomes too short

(c) Shunt capacitive reactance become too large (d) Series inductive reactance become too small

14. Which of the following can be used for amplification of microwave energy? [ ]

(a) Travelling wave tube (b) Magnetron (c) Reflex Klystron (d) Gunn diode

15. The major advantage of TWT over Klystron [ ]

(a) Higher gain (b) Higher frequency (c) Higher output (d) Higher bandwidth


(a) Shot noise (b) Flicker noise (c) Thermal noise (d) Transit time noise

17. Indicate the false statement .transit time in microwave tube will be reduced if [ ]

(a) The electrodes are brought together (b) A higher anode current is used

(c) Multiple or coaxial leads are used (d) The anode voltage is made large

18. The multicavity klystron [ ]

(a) Is not a good low level amplifier because of noise

(b) Has a high repeller voltage to ensure a rapid transit time

(c) Is not suitable for pulsed operation

(d) Needs a long transit time through the buncher cavity to ensure current modulation

19. Indicate the false statement. klystron amplifiers may use intermediate cavities to [ ]

(a) Prevent the oscillations that occurs in two cavity klystron

(b) Increase the bw (c) Improve the power gain (d) Increase the efficiency of the klystron

20. The TWT is sometimes preferred to the multicavity klystron amplifier ,because the formar [ ]

(a) Is more efficient (b)Has a greater bw

(c) Has a higher number of modes (d) Produces a higher o/p power

21. The primary purpose pf the helix in the TWT is [ ]

(a) Prevent the electron beam spreading in the long tube (b) Reduce axial velocity of the rf field

(c) Ensure broadband operation (d) Reduce the noise figure

22. The attenuator in the TWT is used for [ ]

(a) Help focusing (b) Prevent oscillations (c) Prevent saturation (d) Increase gain

23. Periodic permanent magnet focusing is used with TWT t to [ ]

(a) Allow pulsed operation (b) Improve electron bunching

(c) Avoid the bulk of an electromagnet (d) Allow coupled cavity operation at the high frequency

24. Indicate which of the following is not a TWT slow wave structure [ ]

(a) Periodic permanent magnet (b) Coupled cavity (c) Helix (d) Ring bar

25. The glass tube of a TWT may be coated with aquatic to [ ]

(a) Help focusing (b) Provide attenuation (c) Improve bunching (d) Increase gain

26. A reflex Klystron functions as [ ]

(a) Microwave oscillator (b) Microwave amplifier (c) Both A & B (d) A high gain cavity

27. The modes in a reflex Klystron [ ]

(a) Give the same frequency but different transit times

(b) Result from excessive transit time across the resonator gap

(c) Are caused by spurious frequency modulation

(d) Are just for theoretical considerations


(a) Lumped circuit elements (b) Distributed circuit elements

(c) Both A & B (d) None of the above

29. Which of the following can be used for amplification of microwave energy? [ ]

(a) Travelling wave tube (b) Magnetron (c) Reflex Klystron (d) Gunn diode

30. The major advantage of TWT over Klystron [ ]

(a) Higher gain (b) Higher frequency (c) Higher output (d) Higher bandwidth

31. Operating frequency of the reflex klystron is as high as [ ]

(a) 70,000 MHz (b) 50,000 MHz (c) 20,000 MHz (d) 10,000 MHz

32. The microwave tube that uses buncher and catcher cavities is [ ]

(a) Klystron (b) Magnetron (c) Reflex klystron (d) Travelling-wave tube

33. ------ is unlikely to be used as a pulsed device [ ]

(a) BWO (b) TWT (c) CFA (d) Multi-cavity klystron

34. Which of the following statement is false? In microwave tubes Transit time will be reduced if[ ]

(a) The electrodes are brought closer together

(b) Multiple or coaxial leads are used

(c) The anode voltage is made larger

(d) The anode current is made larger

35. What is the primary purpose of the helix in a travelling wave tube? [ ]

(a) To reduce noise figure

(b) To prevent the electron beam from spreading in the long tube

(c) To reduce the axial velocity of the RF field

(d) To ensure broadband operation

36. In multicavity Klystron additional cavities are inserted between buncher and catcher cavities to achieve-

[ ]

(a).Higher Gain (b).Higher Efficiency (c).Higher Frequency (d).Higher Bandwidth

37. A space between two cavities in two cavity klystron is [ ]

(a).Drift space (b).Free space (c).Running apace (d).Normal space

38. TWT is [ ]

(a).Oscillator (b). Tuned Amplifier (c). Wide band Amplifier

(d).Both A & B amplifier and Oscillator

39. Klystron oscillators are most often used in the frequency range of [ ]

(a). 300 to 3000 MHz (b) 3000 to 30000 MHz (c) 30 to 30000 MHz (d) 10 to 10000 MHz

40. The main benefit of using microwaves is [ ]

(a) Lower-cost equipment (b) Simpler equipment

(c) Greater transmission distances (d) More spectrum space for signals

SHORT QUESTIONS

1. Write classifications microwave Tubes. [L1][CO.3][2M]

2. Why conventional tubes does not used at microwave frequencies? [L1][CO.3][2M]

3. What is transit time? [L1][CO.3][2M]

4. Mention the applications of two cavity Klystron. [L6][CO.3][2M]

5. What is velocity and current modulation in a reflex klystron? [L1][CO.3][2M]

6. What is the operating frequency and power output of a reflex klystron? [L1][CO.3][2M]

7. What are the applications of reflex klystron? [L1][CO.3][2M]

8. List four types of slow wave structures. [L1][CO.3][2M]

9. What is the purpose of slow wave structures used in TWT amplifiers? [L1][CO.3][2M]

10. Define bunching. [L2][CO.3][2M]

11. What are the assumptions for calculation of RF power in Reflex Klystron? [L4][CO.3][2M]

12. Why do different modes of operation exist for a reflex klystron? [L1][CO.3][2M]

13. What is the condition for oscillation in Reflex klystron? [L1][CO.3][2M]

14. In klystron what is the use of collector? [L1][CO.3][2M]

15. Explain the need for an attenuator in a TWT amplifier. [L2][CO.3][2M]

16. Give the drawbacks of klystron amplifiers. [L1][CO.3][2M]

17. How the klystron amplifier can act as klystron oscillator? What are the applications of klystron

amplifier? [L1,L6][CO.3][2M]

18. Draw the voltage characteristics of Reflex klystron [L1][CO.3][2M]

19. What are limitations of conventional tubes at microwave frequencies? [L1][CO.3][2M]

20. What do you mean by O-type tubes? Name some O-type tubes. [L1][CO.3][2M]

ESSAY QUESTIONS

1. (a) Give the performance specification of Reflex klystron. [L1][CO.3][4M]

(b) Define and explain current modulation with neat diagrams and required expressions. [L1,L4][CO.3]

[4M]

2. (a) Describe with the neat sketch the constructional details and principle of operation of a reflex

Klystron tube. With the help of Applegate diagram illustrate the phenomenon of bunching. [L1,L4]

[CO.3][5M]

(b) Derive the expressions for bunched beam current and efficiency. [L4][CO.3][5M]

3 (a) Write any two limitations of conventional tubes at Microwave frequencies. [L1][CO.3][4M]

(b) With the help of velocity diagram explain principle of two-cavity Klystron amplifier. [L4,L2]

[CO.3][6M]

4 Discuss in detail about Reflex Klystron and Calculate efficiency. [L2,L4][CO.3][10M]

5 (a) List two discriminations between conventional tube and microwave tube. What can be the possible

Solutions to the limitations of conventional tubes at high frequencies? Which one is the best? [L1]

[CO.3][5M]

(b) Write short notes on bunching process in a two-cavity klystron amplifier. [L1][CO.3][5M]

6 Explain the operation of a two cavity klystron amplifier. Derive expressions for bunched beam current

and efficiency. [L2,L4][CO.3][10M]

7 (a) Why at microwave frequency we talk of traveling waves with associated powers instead of

Voltages and currents? [L1][CO.3][4M]

(b) What are slow wave structures? Explain how a helical TWT achieve amplification. [L2][CO.3][6M]

8 (a) What is a slow wave structure? Draw any four slow wave structures usable in a traveling wave

Tube. [L1,L4][CO.3][4M]

(b) Explain the possibility of oscillations in a TWT amplifier. Suggest method to prevent oscillations.

[L2][CO.3][3M]

(c) Discuss about the differences between a TWT and a Klystron. [L2][CO.3][3M]

9 (a) Write short notes on wave modes. [L1][CO.3][4M]

(d) Mention how a TWT can be converted to an oscillator. Explain the operation of such a device.

Why large tuning range, are possible with such a device? [L2][CO.3][6M]

10 (a) Derive the expressions for propagation constant and output power gain of TWT. [L4][CO.3][6M]

(b) In an O-type traveling wave tube, the acceleration voltage is 4000 V and the magnitude of the axial

electric field is 4 V/m. The phase velocity on the slow wave structure is 1.10 times the average

electron velocity. The operating frequency is 2 GHz. Determine the magnitude of velocity function.

. [L4][CO.3][4M]




Unit-4

Cross-field tubes & Microwave Semiconductor devices1. For 8 cavity magnetron-----no of modes will exists. [ ]

(a) 8 (b) 7 (c) 1 (d) 3

2. For 8 cavity magnetron ,Φv= ----- [ ]

(a)0 (b)45 (c)90 (d)25

3. ----- electrons participating in energy transfer [ ]

(a) Favoured (b) Unfavoured (c)Both A & B (d) None

4. The bunch of electrons in magnetron is known as ----- [ ]

(a) Electron clouds (b) Spokes (c) Both A & B (d) None

5. The theoretical efficiency of TWT is ----- [ ]

(a) 5-20% (b) 50-60% (c) 15-35% (d) 60-80%

6. The theoretical efficiency of Magnetron is ----- [ ]

(a) 5-20% (b) 40-70% (c) 15-35% (d) 60-80%

7. In magnetron at ρ=a,dΦ/dt= ----- [ ]

(a) Zero (b) Maximun (c) Minimum (d) None

8. In magnetron at ρ=a,dρ/dt= ----- [ ]

(a) Zero (b) Maximun (c) Minimum (d) None

9. Solid state devices basically works on the principle of ----- [ ]

(a) Velocity modulation (b) Negative ressistance (c) Positive resistance (d) None

10. The example of negative resistance device is ----- [ ]

(a) IMPATT (b) TRAPATT (c) Gunn diode (d) None

11. The example of TED is ----- [ ]

(a) IMPATT (b) TRAPATT (c) Gunn diode (d) None

12. The example of avalanche transit time device is ----- [ ]

(a) Tunnel diode (b) TRAPATT (c) Gunn diode (d)None

13. Negative resistances devices are called ----- devices [ ]

(a) Passive (b) Active (c) Both A & B (d)None

14. Gunn effect depends on -----theory [ ]

(a) RWH (b) Hall effect (c) Both A & B (d)None

15. The mass of electron is maximum in ----- valley [ ]

(a) Lower (b) Upper (c) Both A & B (d)None

16. The mobility of electron is maximum in ----- valley [ ]

(a) Lower (b) Upper (c) Both A & B (d) None

17. The mass of electron is minimum in ----- valley [ ]


18. The mobility of electron is minimum in ----- valley [ ]


19. ----- substance is used for TEDs [ ]

(a) Al (b) Cu (c) GaAs (d) None

20. TEDs operate with ----- electrons [ ]

(a) Warm (b) Hot (c) Both A & B (d) None

21. The parametric amplifier uses ----- for its amplification [ ]

(a) Resistance (b) Non-linear reactance (c) Controllable impedance (d) None

22. IMPATT is ----- device [ ]

(a) TED (b) ATTD (c) Both A & B (d) None

23. ----- uses an axial magnetic field and radial electric field. [ ]

(a) Reflex Klystron (b) Coaxial Magnetron (c) Travelling wave magnetron

(d) CFA-Crossed Field Amplifier

24. The biggest advantage of the TRAPATT diode over the IMPATT diode is its [ ]

(a) Low noise (b) Higher efficiency

(c) Ability to operate at higher frequencies (d) Lesser sensitivity to harmonics

25. A varactor diode may not be useful at microwave frequencies [ ]

(a) For electronic tuning (b) For frequency multiplication

(c) As an oscillator (d) As a parametric amplifier

26. The negative resistance in a tunnel diode [ ]

(a) Is maximum at the peak point of the characteristic

(b) Is available between the peak and valley points

(c) Is maximum at valley point

(d) May be improved by the use of reverse bias

27. Which one of the following is a transferred electron device? [ ]

(a) BARITT diode (b) IMPATT diode (c) Gunn diode (d) Step recovery diode

28. A PIN diode is suitable for use as a [ ]

(a) Microwave switch (b) Microwave mixed diode (c) Microwave detector (d) None

29. The semiconductor diode which can be used in switching circuits at microwave range is[ ]

(a) PIN diode (b) Tunnel diode (c) Varactor diode (d) Gunn diode

30. In π mode operation of magnetron, the spokes due to phase focusing effect rotate

at an angular velocity corresponding to [ ]

(a) One pole/cycle (b) Two poles/cycle (c) Four poles/cycle (d) Six poles/cycle

31. For Gunn diodes, gallium arsenide is preferred to silicon because the former [ ]

(a) Has a suitable empty energy band, which silicon does not have

(b) Has a higher ion mobility

(c) Has a lower noise at the highest frequencies

(d) Is capable of handling higher power densities

32. Travelling wave parametric amplifiers are used to [ ]

(a) Provide a greater gain (b) Reduce the number of varactor diodes required

(c) Avoid the need for cooling (d) Provide a greater bandwidth

33. The cavity magnetron use strapping to [ ]

(a) Prevent mode jumping (b) Prevent cathode back heating

(c) Ensure bunching (d) Improve the phase focusing

34. A magnetic field is used in the cavity magnetron to [ ]

(a) Prevent anode current in the absence of oscillations

(b) Ensure that the oscillations r pulsed

(c) Help in focusing the electron beam, thus preventing spreading

(d) Ensure that the electrons will orbit around the cathode

35. The biggest advantage of the trapatt diode over the impatt diode is it's [ ]

(a) Lower noise (b) Higher efficiency

(c) Ability to operate at higher frequency (d)Lesser sensitivity to harmonics

36. One of the following microwave diode is suitable for very low power oscillator only [ ]

(a) Tunnel (b) Avalanche (c) Gunn (d) Impatt

37. The transferred-electron bulk effect occurs in [ ]

(a) Germanium (b) Gallium arsenide (c) Silicon (d) Metal semiconductor junctions

38. The tunnel diode [ ]

(a) Has a tiny hole through it's centre to facilitate tunnelling

(b) Is a point contact diode with a very high reverse resistance?

(c) Uses a high doping level to provide a narrow junction

(d) Works by quantum tunnelling exhibited by gallium arsenide only

39. A magnetron is used only as [ ]

(a) Amplifier (b) Oscillator (c) Mixer (d) Frequency multiplier

40. Radar stands for [ ]

(a)Radio Distance and Ranging (b) Radio Detection and Ranging

(c)Radio Direction and Ranging (d) Radio Distance and Range

SHORT QUESTIONS

1. Why magnetron is called as cross filed device? [L1][CO.4][2M]

2. What is π mode of operation? [L1][CO.4][2M]

3. Give the Hull cutoff and Hartree conditions of Cylindrical Magnetron. [L1][CO.4][2M]

4. List the type of circuit used for IMPATT diode circuits. [L1][CO.4][2M]

5. What is negative resistance? [L1][CO.4][2M]

6. Mention some applications of Gunn diode. [L6][CO.4][2M]

7. What is Transferred electron effect? [L1][CO.4][2M]

8. What is the parametric device? [L1][CO.4][2M]

9. Write the applications of parametric amplifier. [L6][CO.4][2M]

10. Write different microwave signal sources. [L1][CO.4][2M]

11. What is the operating frequency of TRAPATT devices?? [L1][CO.4][2M]

12. Define GUNN EFFECT. [L2][CO.4][2M]

13. What are the factors reducing efficiency of IMPATT diode? [L1][CO.4][2M]

14. Can Gunn diodes can serve as microwave frequency generators? [L1][CO.4][2M]

15. Compare Avalanche transit time devices. [L3][CO.4][2M]

16. Leaving reflex klystron, what other devices are used as microwave signal sources?[L1][CO.4][2M]

17. What is the main advantage of TRAPATT over IMPATT? [L1][CO.4][2M]

18. Why are FET’s preferred to bipolar transistor at high frequencies? [L1][CO.4][2M]

19. List out the applications of Gunn and TRAPATT diodes. [L6][CO.4][2M]

20. What are the Key phenomenon taking places in TRAPATT diode? [L1][CO.4][2M]

ESSAY QUESTIONS

1. Explain the growth of oscillations in a travelling wave magnetron. [L2][CO.4][10M]

2. Discuss in detail about cylindrical magnetron. [L2][CO.4][10M]

3. (a) Explain the properties of high field domain for microwave generation and amplification. . . .

… [L2][CO.4][5M]

(b) Explain the rate of growth of space charge layers with the help of necessary expressions.

[L2,L4][CO.4][5M]

4. (a) What is transferred electron effect? [L2][CO.4][4M]

(b) Explain clearly how a GUNN diode is different from a tunnel Diode Both A & B being a negative

resistance devices. [L2][CO.4][6M]

5. (a) What is parametric amplifier? [L1][CO.4][4M]

(b) Explain it as an amplifier and frequency converter. [L2][CO.4][6M]

6. (a) Explain the V-I characteristics of a Gunn diode [L2][CO.4][5M]

(b) List the differences between microwave transistor and TED devices. [L1][CO.4][5M]

7. (a) Give the classification of solid state microwave devices along with examples? [L1][CO.4]

[6M]

(b) An n-type GaAs Gunn diode has following parameters:

Electron drift velocity: vd = 2.5 × 105 m/s.

Negative electron mobility: µn = 0.015 m2/ v. s.

Relative dielectric constant: €r = 13.1.

Determine the criterion for classifying the modes of operation [L4][CO.4][4M]

8. Discuss how a decrease in drift velocity with increasing electric field can lead to the formation of a

high field domain for microwave generation and amplification. [L2][CO.4]

[10M]

9. (a) Discuss in detail about Gunn diode modes of operation. [L2][CO.4][5M]

(b) What are bulk properties of a GUNN diode that give rise to negative resistance like

characteristics? . [L1]

[CO.4][5M]

10. (a) Explain Two Valley Model Theory. [L2][CO.4][6M]

(b) Write short notes on “TRAPATT diode”. [L1][CO.4][4M]




Unit-5

Microwave Measurements1. ----- is the device that generate mw power [ ]

(a) Magnetron (b) TWT (c) Reflex klystron (d) None

2. Low power can be measured by using ----- technique [ ]

(a) Bolometer ( b) Galvanometer (c) Watt meter (d) None

3. Thermister is ----- device [ ]

(a) PTC (b) NTC (c) Both A & B (d) None

4. In baratter the rate of resistance change is ----- [ ]

(a) 5Ω/mw ( b) 50Ω/mw (c) 60Ω/mw (d) None

5. RF substitution method can be used to measure ----- [

]

(a) Frequency (b) Power (c) Attenuation (d) VSWR

6. The attenuation can be measured by ----- technique [ ]

(a) Bolometer (b) Power ratio (c) Slotted line (d) None

7. In impedance measurement ,if vmin shifts left then impedance is ----- [ ]

(a) Capacitive (b) Inductive (c) Resistive (d) None

8. The range of VSWR is ----- [ ]

(a) 0-1 (b) 1-∞ (c) 1-10 (d) None

9. Double minimum method can be used to measure ----- [ ]

(a) Impedance (b) Attenuation (c) High VSWR (d) None

10. The quality factor QL= ----- [ ]

(a) 2/Δ (b) 1/Δ (c) 1/2Δ (d) None

11. In wave meter technique, the output power is ----- when fun=f0 [ ]

(a) Maximum (b) Minimum (c) Zero (d) None

12. Impedance can be measured using ----- technique [ ]

(a) Magic tee (b) Slotted line (c) Reflectometer (d) None

13. Reflectometer technique can be used to measure ----- [ ]

(a) Impedance (b) VSWR (c) Both A & B (d) None

14. Magic tee can be used to measure ------ [ ]

(a) Impedance (b) Attenuation (c) Frequency (d) None

15. High VSWR can measured by ----- technique [ ]

(a) Bolometer (b) Power ratio (c) Double minimum method (d) None

16. In wave meter technique, the wave meter will ----- the power when fun=f0 [ ]

(a) Absorbs (b) Transmits (c) No action (d) None

17. Reflection coefficient ρ= ----- [ ]

(a) Pin/ Pref (b) Pref*Pin (c) Pref/Pin (d) None

18. Most of the power measuring microwave devices measure [ ]

(a) Average power (b) Peak power (c) Instantaneous power (d) None

19. HEMT used in microwave circuit is a [ ]

(a) Source (b) High power amplifier (c) Detector (d) Low noise Amplifier

20. In microwave power measurements using bolometer, the principle of working

is the variation of [ ]

(a) Inductance with absorption of power (b) Resistance with absorption of power

(c) Capacitance with absorption of power (d) Cavity dimensions with heat generated by the power


(a) Lumped circuit elements (b) Distributed circuit elements (c) Both A & B (d) None

22. For handling large microwave power, the best medium is [ ]

(a) Coaxial line (b) Rectangular waveguide (c) Stripline (d) Circular waveguide

23. Ionosphere preparation is not possible for microwaves because [ ]

(a) Microwaves will be fully absorbed by the ionospheric layers

(b) There will be an abrupt scattering in all directions

(c) Microwave will penetrate through the ionospheric layers

(d) There will be dispersion of microwave energy

24. A waveguide section in a microwave circuit will act as a [ ]

(a) Low-pass filter (b) Band-pass filter (c) High-pass filter (d) Band-reject filter

25. A varactor diode may not be useful at microwave frequencies [ ]

(a) For electronic tuning (b) For frequency multiplication

(c) As an oscillator (d) Parametric amplifier

26. The negative resistance in a tunnel diode [ ]

(a) Is maximum at the peak point of the characteristic

(b) Is available between the peak and valley points

(c) Is maximum at valley point

(d) May be improved by the use of reverse bias

27. A PIN diode is suitable for use as a [ ]

(a) Microwave switch (b) Microwave mixed diode (c) Microwave detector (d) None

28. Due to curvature of earth, microwave repeaters are placed at a distance of about [ ]

(a) 10 Km (b) 50 Km (c) 150 Km (d) 250 Km

29. At microwave frequencies the size of the antenna becomes [ ]

(a) Very large (b) Large (c) Small (d) Very Small


(a) Shot noise (b) Flicker noise (c) Thermal noise (d) Transit time noise

31. The phenomenon of microwave signals following the curvature of earth is known as [ ]

(a) Faraday effect (b) Ducting (c) Wave tilt (d) Troposcatter

32. Indicate which of the following cannot be followed by the word waveguide [ ]

(a) Elliptical (b) Flexible (c) Coaxial (d) Ridged

33. For low attenuation best transmission medium is [ ]

(a) Flexible waveguide (b) Ridged waveguide (c) Rectangular waveguide (d) Coaxial line

34. The glass tube of a TWT may be coated with aquadag to [ ]

(a) Help focusing (b) Provide attenuation (c) Improve bunching (d) Increase gain

35. One of the following is not used as a microwave mixer or detector [ ]

(a) Crystal diode (b) Schottky barrier diode (c) Backward diode (d) Pin diode

36. The tunnel diode [ ]

(a) Has a tiny hole through it's center to facilitate tunneling

(b) Is a point contact diode with a very high reverse resistance

(c) Uses a high doping level to provide a narrow junction

(d) Works by quantum tunnelling exhibited by gallium arsenide only

37. A tunnel diode is loosely coupled to it's cavity in order to [ ]

(a) Increase the frequency stability

(b) Increase the available -ve resistance

(c) Faciliting tuning

(d) Allow operation at the high frequency

38. --- is a object detection system that uses microwaves [ ]

(a) Microwave oven (b) Transmitter (c) Radar (d) Satellite

39. ---- is an electronically controlled home appliance used for cooking [ ]

(a) Radar (b) Microwave oven (c) Satellite (d) None

40. Speed of em wave in free space is ------ [ ]

(a) 3 x 1010m/s (b) 3 x 1012cm/s (c) 3 x 1010cm/s (d) None

SHORT QUESTIONS

1. Define VSWR and Reflection coefficient. [L1][CO.5][2M]

2. Draw the block diagram of microwave bench. [L4][CO.5][2M]

3. What do you mean by slotted line? [L1][CO.5][2M]

4. What is Bolometer and calorimeter? [L1][CO.5][2M]

5. What is a VSWR meter? [L1][CO.5][2M]

6. Distinguish between low frequency measurements and microwave measurements. [L4][CO.5][2M]

7. Distinguish between thermistor and barrette? [L4][CO.5][2M]

8. What are the precautions taken while measuring microwave measurements? [L1][CO.5][2M]

9. What are the methods measuring attenuation and Impedance. [L1][CO.5][2M]

10. What is spectrum analyzer and list different spectrum analyzer’s. [L1][CO.5][2M]

11. Distinguish between the terms: Insertion Loss and Attenuation. [L4][CO.5][2M]

12. How are microwave measurements different from low frequency measurements? [L1][CO.5][2M]

13. Describe use of dc ammeter at microwave frequencies. [L1][CO.5][2M]

14. Write short notes on usage of Isolator and its significance in a microwave bench. [L1][CO.5][2M]

15. List some application of spectrum analyzer. [L6][CO.5][2M]

16. How do you measure microwave frequency? [L1][CO.5][2M]

17. List the types of spectrum analyze. [L1][CO.5][2M]

18. Define the term Q factor for a cavity and Tunable Probe. [L1][CO.5][2M]

19. Two identical 30dB directional couplers are used to sample incident and reflected power in a wave

guide, VSWR=2 and the output of the coupler sampling incident power=4.5mW.What is the value of

reflected power. [L4][CO.5][2M]

20. What is network analyzer? [L1][CO.5][2M]

ESSAY QUESTIONS

1. (a) Distinguish between low frequency measurement and microwave measurements. [L4][CO.5][4M]

(b) With the help of a neat sketch, briefly explain the functions of different blocks of a microwave

bench. [L2][CO.5][6M]

2. (a) Discuss about the

important

considerations when

making attenuation

measurement. [L1]

[CO.5][5M]

(b) Explain about measurement of attenuation using a microwave bench setup. [L2][CO.5][5M]

3. (a) Discuss in detail about measurement of VSWR. [L2][CO.5][6M]

(b) Determine s-parameters of a 10 dB directional coupler of directional coupler of Directivity 30

dB. Assuming directivity of coupler loss-less VSWR at each port under Matched condition is

unity. . [L4][CO.5]

[4M]

4. (a) What is spectrum analyzer? List the types of spectrum analyzer. List some application of

Spectrum analyzer. [L1,L6]

[CO.5][6M]

(b) Describe a microwave bench. [L4][CO.5][4M]

5. (a) How to measure an attenuation of a given microwave signal? [L2][CO.5][4M]

(b) What is VSWR? Explain the method measurement for low and high VSWR?. [L2][CO.5][6M]

6. (a) Distinguish between the terms: Insertion Loss and Attenuation. With a neat set up, describe the

method of measurement of attenuation using a waveguide bench. [L4][CO.5][6M]

(b) Write short notes on usage of Isolator and its significance in a microwave bench. [L1][CO.5][4M]

7. (a) Write a short note on power ratio method. [L1][CO.5][5M]

(b) Write short notes on RF substitution method. [L1][CO.5][5M]

8. (a) Two identical directional couplers are placed in a waveguide to sample the incident and the

reflected

power. The meter readings show that the power level of the reverse coupler is 10dB down from the

level of the forward coupler. What is the value of the SWR on the waveguide? [L4][CO.5][4M]

(b) How are microwave measurements different from low frequency measurements? [L1][CO.5][6M]

9. (a) Draw the experimental setup necessary for the measurement of impedance using slotted line.

Explain in detail. [L4,L2][CO.5][5M]

(b) What are the characteristics of detectors used in microwave measurements? [L1][CO.5][5M]

10 (a) Discuss in detail about measurement of attenuation. [L2][CO.5][4M]

(b) Write short notes on “Reflection co-efficient and Insertion loss measurement at microwave

frequencies”. [L1][CO.5][6M]

Documents

sietkece.comsietkece.com/wp-content/uploads/2016/08… · Web view · 2017-01-23The biggest advantage of the trapatt diode over the impatt diode is it's [ ] (a) Lower noise (b)