摘要 |
A transducer for use in a hybrid optical and radio communications system includes a zero electrical power photodetector and a radio antenna. The photodetector is electrically connected to the radio antenna so that, in use, optical signals are received and radio signals are transmitted by the transducer without the use of electrical power. The transducer can thus be remotely sited at locations in communications systems not having a supply of electrical power. In a first embodiment the photodetector includes a zero-bias photodiode, and in a second embodiment the transducer includes a self-biasing photodetector. |