Correlator for determining signal propagation time in receiver - obtains reference from digitised and stored input for switching to HF stage alternating with antenna connection.

摘要

The appts. applies a signal received from an antenna to a high-frequency input stage (1) contg. two mixers (1.ZF,2.ZF) for amplification. The resulting signal is band-pass filtered (BP) and digitised (2) for processing (SP). The digital signal is read from memory (ST) to a D/A converter (3) with a low-pass filter (TP) driving an analogue processor (4) whose output is matched (PA) to the HF input when the antenna switch is reset by a control circuit (AS) incorporated in the digitiser. USE/ADVANTAGE - In radio direction-finding and location, reference for correlation purposes is derived from received transmission and requires no additional calibration signal. Propagation delay is measured exactly.