| 摘要 |
<p>Terminals using a two-way RF signal with a downlink channel and an uplink channel, which downlink channel includes a pilot frequency (13) corresponding to the carrier frequency modulating the uplink channel. Corresponding user terminals use an oscillator synchronised with said downlink channel pilot frequency to provide intermediate frequency translation of the downlink channel signals, as well as translation of the uplink channel signals around said pilot frequency. A broadcasting station terminal uses a high-stability microwave oscillator to generate said pilot frequency as well as to provide intermediate frequency translation of the uplink channel signals. The terminals are particularly useful for setting up a feedback channel, especially in the frequency band of millimetric or centimetric wavelengths.</p> |
