Microwave propagation time measurement appts. - has receiver with compensation circuit forming sink for integrating echo signals in receiver

摘要

The propagation time measurement apparatus includes a transmitter (1,3) sending signals towards the object or region to be monitored. A receiver (4,5,6) shifts the reflected echo signal in frequency using a mixer (5). The mixer mixes the reflected echo signal with a sampling signal. The frequency shifted signal is supplied to an evaluation circuit which evaluates its propagation time. The receiver has a compensation circuit which forms a sink for interference echo signals in the receiver or associated components. ADVANTAGE - Removes or at least reduces interfering effect of internally generated interference echo signals.