Patent ID: 8229372
Filing Date: 2012-07-24
Classification: H03F

Abstract:
1. An RF amplifier stage comprising a feedback loop having parallel main and auxiliary forward paths connected by at least one coupler, each of the main and auxiliary forward path having a mixer through which signals are upconverted to a carrier frequency and an amplifier that amplifies the upconverted signals prior to transmission, the main forward path having a main RF power amplifier and the auxiliary forward path having an auxiliary RF power amplifier with less latency and providing a smaller power output than the main RF power amplifier, main and auxiliary mixers respectively disposed in the main and auxiliary forward paths being supplied with local oscillator signals of the same frequency and different phases such that synchronous modulation and demodulation is achieved for both main and auxiliary loops of the feedback loop, wherein the main and auxiliary forward paths are filtered such that the main forward path carries signals of lower frequencies than the auxiliary forward path.