| 摘要 |
Transponder system comprising an FMCW radar transceiver (1) arranged to transmit an FMCW signal (2) and to receive the backscattered reflections (3). The transponder (4) comprises an antenna (5) connected to a switch (6), arranged to modulate the terminating impedance of the antenna, thus modulating the backscattered signal. The modulating switch is controlled by digital control means (7, 10) arranged to be controlled by voice (9) or data produced by a human user, thus using the transponder as a communication device for digital voice or data from the user to the transceiver, which communication cannot be intercepted by any external system. The FMCW transceiver can measure the distance and direction of the transponder. The system is very attractive for military etc. operations. The reflected signal may be frequency shifted and amplified by a booster module (20,21). |
