Question

Two scientists are in a desert. They are equipped with identical handheld radios operating at 1800 MHz. When transmitting, the radio’s transmitter power supplied to the transmitting antenna is 0 dBW. Assume that the desert surface is smooth and flat. The desert ground is assumed to be a lossless dielectric material with relative permittivity εr = 6.25 and relative permeability µr = 1. Assume also that the radios’ antennas are vertical (with respect to the ground) infinitesimal electric dipoles. The distance between the scientists is 1 km. They hold their radios vertically at heights of 1.7 m above the ground. Determine the signal power received by each radio from the other. Show all the calculation steps. State all the assumptions you make. Additional Information Required to Answer this Question: Prior to going to the desert the scientists calibrated their radios in an electromagnetic anechoic chamber. Separating the radios by 10 m, and aligning them for maximum power transfer, they found the received signal power at each radio from the other was 2.97 µW.

Answer 1

The question is solved using Friss transmission equation, the gain of the radio is initially found and then substituted to get the

received power. The value of c is found based on the given values of epsilon and mu.