A pulse radar ranging system

摘要

In a pulse radar ranging system, directional coupling means (6) are designed to convey transmit pulses (TX) to be transmitted via an antenna (8) to a target (9) and to convey target echoes (RX) received by the antenna (8) to a signal mixer (10) that generates an intermediate frequency signal (IF). To embed a reference measurement into the target measurement, the directional coupling means (6) comprises a four-port circulator having an additional port (6b) arranged between a port (6a) receiving the transmit pulses (TX) and a port (6c) coupled to the antenna (8). A reference line (7) is coupled to said additional port (6b) for generating reference echo pulses (RX') in response to input pulses. The circulator (6) is designed to split a portion (TX') of the transmit pulses (TX) to the reference line (7) and to convey the reference echo pulses (RX') to the antenna (8).