| 摘要 |
<p>An electronic system for accurately controlling the RF output power from a power amplifier (21) is implemented using a multiplier (28) which multiplies the output power by itself to provide a DC component which is fed to a variable gain amplifier (29) which provides a controlling signal via a comparator (24) and an integrator (25) to the power amplifier. The transfer function between controlling signal and output power is substantially linear, even during dynamic variation of the controlling signal. The system is capable of a large dynamic range, and exhibits constant control loop bandwidth over this range. This is of particular use to TDMA applications with a large dynamic range of levelled output powers because a fixed filter function can be used to shape the transmitted burst.</p> |
