| 摘要 |
A radio frequency (RF) receiver circuit (2) comprises: an antenna (8) for receiving a radio frequency (RF) signal (4); an optical detector (10) for receiving a modulated optical signal (12) and converting it to an electrical signal; means (14) for mixing the electrical and RF signals to produce an intermediate frequency signal; and a reflective optical modulator (16) which is operable at the intermediate frequency to modify and reflect (24) the modulated optical signal (12) with the intermediate frequency. By detecting the optical signal which has been modified by the circuit, it is possible to remotely detect the RF signal received by the circuit and the circuit thus acts as a remotely accessible RF receiver circuit. A transmitter arrangement and aerial tuning are also described. |
