Research Of CW Radar's Broadband Transmit Leakage Canceling Technology

CW radar has many advantages to pulse radar, such as: high precision on distance measurement, excellent ability on compressing clutter in spectrum, excellent identifying ability of moving target, high transmitting efficiency. At the same time, there is much transmit leakage in the CW radar. This paper introduces the cause of direct coupling in FMCW radar and the leakage from transceiver antenna, and effect on the sensitivity of the receiver. Finally, several means to restrain the leakage from FWCW and PMCW radar transmitter are discussed, such as: microwave adaptive canceling, IF adaptive canceling of which the math model, electronic principle and the effect are concerned here.In addition, this paper is emphasized on the engineer design of canceling system. The author has designed a receiver system involving several canceling technology on demand of practice, as well as analyses the design program of main module and key point of engineer design. Finally, there are analysis of system test data and the develop trend of the canceling technology in the paper.