Microwave Communication Questions

• Which mode has the minimum cutoff frequency in rectangular wave guides?
• The radiation resistance of a doublet antenna of length dl is proportional to
• Assertion (A): A small section of high impedance line is equivalent to a series inductance. Reason (R): A small section of a low impedance line is equivalent to a series resistance.
• When duct propagation exists
• As compared to dimensions of most feeds, the skin depth at microwave frequencies is
• In which mode of rectangular waveguide are all field components zero?
• A microstrip line has dielectric having relative permittivity ∈r. The effective dielectric constant is
• If in line the characteristic impedance becomes real.
• Consider the following statements about radar Beacon It is also called transponder. It includes pulse transmitter, receiver and antenna. It replies with full power even when the signal receives is weak. Which of the above statements are correct?
• For l << λ, the equivalent circuit of a microwave resistor is
• The usable bandwidth of ridge wave guide
• A short circuited stub is preferred to an open circuited stub because an open circuited stub
• A square waveguide carries TE11 mode whose axial magnetic field is given by Hz = H0 , where the guide dimensions are in cms. The cut off frequency of the mode is
• If air pressure in a rectangular waveguide is increased the maximum power handling capacity
• The noise figure of klystron amplifier is about
• If the peak transmitted power in a radar is increased by a factor 81, the maximum range is increased by a factor of
• Which of the following statements is not correct regarding modes of electromagnetic energy transmission?
• In 8 cavity magnetron the p mode corresponds to a total phase shift equal to
• Oscillations are obtained from a reflex klystron only for combinations of anode voltage and repeller voltage that give a favourable transit time.
• In microwave communication links the fading due to rain occurs. The methods to solve this problem include