Patent ID: 7170953
Filing Date: 2007-01-30
Classification: H03F,H03G,H04B,H04W

Abstract:
1. An upconversion and amplification apparatus for use in a transmitter that provides an amplified differential signal having substantially constant output power and containing, over time, data from a plurality of data packets, each data packet including a plurality of training symbols towards a beginning of the packet, the apparatus comprising: a variable gain amplifier having a variable gain, the variable gain amplifier inputting a differential signal and outputting an amplified differential signal; a power amplifier electrically coupled to the variable gain amplifier, the power amplifier inputting the differential signal or a signal deriving from the amplified differential signal and outputting a power amplified differential signal having an output power; a power detection circuit including a power detector that is coupled to the power amplification stage and provides a detected power signal indicating the output power such that the detected power signal is created at an interval that is at least once per symbol during some of the plurality of training symbols; and a power control circuit electrically coupled to the power detection circuit, and the variable gain amplifier, the power control circuit: increasing the variable gain of the variable gain amplifier in a step increment when the detected power signal, as detected during each of the some of the plurality of data training symbols during each packet transmission, is lower than a predetermined power; and decreasing the variable gain of the variable gain amplifier in a step decrement when conditions require so that the detected power signal will not exceed an output power threshold.