Microwave Communication Questions

• Assertion (A): The phenomenon of differential mobility is called transferred electron effect. Reason (R): GaAs exhibits transferred electron effect.
• A line is excited by a 100 V dc source. If reflection coefficients at both ends are 1 each then
• Reflex klystron oscillator is essentially a low power device
• A resistive microwave load with ZL = 150 Ω is connected to 50 Ω coaxial line. SWR is
• Assertion (A): A backward wave oscillator has an internal positive feedback. Reason (R): A positive feedback is necessary for sustained oscillations.
• The velocity factor of a transmission line depends on
• A line has a phase constant of 29.8 rad/m. At 1000 MHz the wavelength is
• The diagram to show distance time history of electrons in klystron amplifier is called
• In a circular waveguide the dominant mode is
• In a travelling wave tube distributed interaction between an electron beam and a travelling wave takes place
• In a klystron amplifier dc electron velocity is v0 and dc electron charge density is r0 the dc beam current is
• Assertion (A): A coaxial line is a non-radiating line. Reason (R): In a coaxial line the electric and magnetic fields are confined to the region between the concentric conductors.
• A loss less line of characteristic impedance Z0 is terminated in pure reactance of -jZ0 value. VSWR is
• In a directional coupler
• The action of backward wave oscillator is similar to that of
• In the given figure the reflection coefficient at source end is
• The condition of minimum distortion in a transmission line is
• In a microstrip transmission the signal can be easily redirected by changing the centre strip.
• The width of a radio beam from a 1 m diameter parabolic antenna at 10 GHz is about
• Both Impatt and Trapatt devices use avalanche effect