Patent ID: 6819938
Filing Date: 2004-11-16
Classification: H04B,H04W

Abstract:
A system for the control of transmit power in wireless communication device having a transmitter and a receiver, the receiver having a calibrated receiver signal pathway capable of determining the strength of a received signal, the system comprising:a variable gain radio frequency (RF) transmitter amplifier having an amplifier input and an amplifier output and a variable gain control input, the variable gain control input initially receiving a control signal indicative of a desired transmit power level; a mixer coupled to the amplifier output and receiving an oscillator signal having an oscillator frequency corresponding to an operational frequency of the receiver, the mixer generating a signal at operational frequency of the receiver and corresponding to a signal at the amplifier output; and a coupling circuit to couple the signal generated by the mixer to the receiver signal pathway to permit power measurement of the signal using the calibrated receiver signal pathway, wherein the coupling circuit comprises a single-pole-single-throw (SPST) type switch to couple the signal generated by the mixer to the receiver signal pathway; wherein the receiver comprises a first receiver variable gain amplifier in the receiver signal pathway, the system further comprising a second receiver variable gain amplifier having an input coupled to the SPST type switch and an output coupled to the receiver signal pathway to couple the signal generated by the mixer to the receiver signal pathway.