Microwave Communication Questions

• Which of the following modes of transmission will not be supported by a rectangular waveguide?
• If 'a' is the width of rectangular wave guide and 'λ' is the wave length, then
• Which one of the following can be used for amplification of microwave energy?
• The transit time (in cycles) for electrons in repeller space of reflex klystron oscillator for sustaining oscillations is (n is any integer)
• If D is diameter of circular waveguide the cutoff wave-length for TE11 mode is equal to
• In the given figure forward current wave has a magnitude of
• The two terms used to describe performance of a directional coupler are
• Consider the following statements Gunn diode can be used in combinational logic circuits. Gunn diode can be used in sequential logic circuits. Both Gunn diode and GaAs Mesfet can be used in logic circuits. Which of the above statements are correct?
• The external magnetic field in a magnetron is such that lines are
• To ensure that only dominant mode TE10 is allowed to propagate in an air filled rectangular waveguide, the lower frequency limit and upper frequency limit are
• A radar has a maximum range of 120 km. The maximum allowable pulse repetition frequency for unambiguous reception is
• A disadvantage of microstrip line as the connections of compared to strip line is that former
• Consider the following time parameters Domain growth time constant. Transit time. Dielectric relaxation time in positive mobility regime. Which of the above are used in connection width transferred electron device?
• In a circular waveguide with radius r, the dominant mode is
• A circular polarizer converts a linearly polarized wave into a circularly polarised wave.
• For a rectangular waveguide having width a and height b, the cutoff wavelength for TM11 mode is equal to
• A circular waveguide carries TE11 mode whole radial electric field is given by Er = E0j1(r) sin Φ V/m where r is radial distance in cm from the axis The cut off wavelength is
• A 75 ohm line is first short terminated and minima locations are noted. Then the short is replaced by resistive load and minima location are again noted. If minima location are not altered and VSWR is 3, the value of resistive load is
• As frequency increases, the transmission efficiency
• A parametric amplifier uses