| 摘要 |
An RF power amplifier is provided having means for defining rise and fall envelopes of the RF power, i.e. the key and de-key characteristics. A power amplifer (10), detector (13) and regulator (15) form a power control feedback loop. A further regulator (21) is provided having a first input coupled to the output of the power control loop regulator and an output coupled to the input of the power control loop regulator, thereby providing negative feedback to the power control loop regulator. Means are provided, coupled to a second input of the further regulator for providing a rising and falling control signal (Vramp) for control of the power amplifier. <IMAGE> |
