Circuit for testing the function of mobile receiving installations

摘要

A circuit for testing the function of mobile radio receiving installations is provided, wherein the circuit generates an HF-output signal that is used to test the system. A frequency mixer receives an oscillation signal (8) generated from within the superheterodyne receiver and an IF-carrier oscillation signal (32) generated from and oscillator (7) within the circuit. The frequency mixer generates an HF-output signal (12) that is dependent on the amplitude and frequency of the received oscillation signals. In alternative embodiments of the invention, the circuit of the invention is incorporated into the superheterodyne receiver, and the generated IF-carrier frequency 32 is eliminated and replaced with an IF-signal 22 produced by self-excitation of the superheterodyne receiver. With multi-antenna scanning diversity systems, additional switches and switching signals are included.