Electronic Communication Systems 2nd Edition by Roy Blake

تمرين 18

A transmitter has an output power of 50 W. It is connected to its antenna by a feedline that is 25 m long and properly matched. The loss in the feedline is 5 dB/100 m. The antenna has a gain of 8.5 dBi.
(a) How much power reaches the antenna
(b) What is the EIRP in the direction of maximum antenna gain
(c) What is the power density 1 km from the antenna, in the direction of maximum gain, assuming free-space propagation
(d) What is the electric field strength at the location in part (c)
(a)

(b)

(c)

(d)