Q.6 The maximum radiation intensity of a 90% efficiency antenna is 200 solid angle. Find the directivity and gain (dimensionless and in dB) when the (a) Input power is 125.66 mW (b) Radiated power is 125.66 mW

Design a rectangular microstrip patch antenna, based on the dominant mode, that can be mounted on the roof of a car to be used for satellite cellular telephone. The designed center frequency is 1.6 GHz, the dielectric constant of the substrate is 10.2 (i.e., RT/duroid), and the thickness of the substrate is 0.127 cm. Determine the (a) dimensions of the rectangular patch (in cm) (b) resonant input impedance, assuming no coupling between the two radiating slots (c) mutual conductance between the two radiating slots of the patch (d) resonant input impedance, taking into account coupling (e) position of the feed to match the patch antenna to a 75-ohm line

a rectangular air-filled copper waveguide with dimension 2.28 cm x 1.01 cm across section  and 30.48 cm length is operated at 9.2 GHz with a dominant mode. Find a)characteristic impedance  b) attenuattion in dB

At 20 GHz, the gain of a parabolic dish antenna of I meter diameter and 70%efficiency is-------