Question

If the earth station downlink signal received is at fs = 4.08 GHz, what first stage local-oscillator frequency fLO is needed to achieve IF of 770 MHz?

(a) 3310 MHz

(b) 4080 MHz

(c) 1203 MHz

(d) 3250 MHz

This question was addressed to me at a job interview.

The query is from Ground Stations topic in division Satellite Communication of Avionics

Answer 1

Right answer is (a) 3310 MHz

To explain: fIF = fs – fLO

fLO = fs – fIF = 4080 – 770 = 3310 MHz.