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  • Question

  • Which one of the following is transferred locking electron device C antenna?


  • Options
  • A. BARITT diode
  • B. IMPATT diode
  • C. Gunn diode
  • D. Step recovery diode

  • Correct Answer
  • Gunn diode 

    Explanation
    A Gunn diode uses GaAs which has a negative differential mobility, i.e., a decrease in carrier velocity with increase in electric field.

    This effects is called transferred electron effect. The impedance of a Gunn diode is tens of ohms.

    A Gunn diode oscillator has a resonant cavity, an arrangement to couple Gunn diode to cavity, biasing arrangement for Gunn diode and arrangement to couple RF power to load.

    Applications of Gunn diode oscillator include continuous wave radar, pulsed radar and microwave receivers.

    Microwave Communication problems

    Search Results

    • 1. If a line having Z0 = 300 ? 0 W is open circuited at far end, VSWR is

    • Options
    • A. 0
    • B. 1
    • C. ?
    • D. 2
      • Discuss
    • 2. The main feature of a parametric amplifier is

    • Options
    • A. low noise
    • B. very high gain
    • C. broad bandwidth
    • D. both (b) and (c)
      • Discuss
    • 3. In microwave system the function of mode filter is

    • Options
    • A. to suppress modes with lower cut off frequencies
    • B. to suppress modes with higher cut off frequencies
    • C. to change mode of wave transmission
    • D. both (b) and (c)
      • Discuss
    • 4. The width of a radio beam from a 1 m diameter parabolic antenna at 1 GHz is about

    • Options
    • A. 100°
    • B. 50°
    • C. 5°
    • D. 2°
      • Discuss
    • 5. A balun should have

    • Options
    • A. low SWR at both ports
    • B. high SWR at both ports
    • C. high SWR at input port and low SWR at output port
    • D. low SWR at input port and high SWR at output
      • Discuss
    • 6. The directive gain of a transmitting antenna is proportional to

    • Options
    • A. its cross-sectional area
    • B. square of cross-sectional area
    • C. square root of cross-sectional area
    • D. cube root of cross-sectional area
      • Discuss
    • 7. A magnetron requires an external magnetic field with flux lines parallel to axis of cathode

    • Options
    • A. True
    • B. False
      • Discuss
    • 8. High speed logic circuits use

    • Options
    • A. pulses with very small width
    • B. pulses with very large width
    • C. pulses whose width is neither small nor large
    • D. either (b) or (c)
      • Discuss
    • 9. The total field developed by an antenna array at a distant point is

    • Options
    • A. phasor sum of fields produced by individual antennas of the array
    • B. algebraic sum of fields produced by individual antennas of the array
    • C. either (a) or (b) depending on type of array
    • D. neither (a) nor (b)
      • Discuss
    • 10. A (75 - J50) ohm load is connected to a coaxial of Z0 = 75 ohm at 10 GHz. The best method of matching is to connect

    • Options
    • A. an inductance at load
    • B. a short circuited stub at load
    • C. a short circuited stub at specific distance from load
    • D. a capacitance at specific distance from load
      • Discuss

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