Abstract: A calibration device for a phase locked loop arranged to generate an output frequency based upon a first frequency range of an input signal applied to a first input and a second frequency range of the input signal applied to a second input, the calibration phase locked loop synthesizer device comprising an estimator arranged to use a two dimensional estimation algorithm with a signal value indicative of a mismatch between the first input path and the second input path to determine an estimate of the mismatch to allow matching of the first input path and the second input path.

Abstract: A transmitter circuit (200, 400, 510) and method reduces amplitude modulation distortion in an amplifier (210). The transmitter circuit (200, 400, 510) includes a power control error data generator (230), a feedforward predistortion data generator (240), feedforward adder logic (250) and the amplifier (210). The power control error data generator (230) receives amplitude modulation data (252) and an RF coupled output signal (254) and, in response, produces power control error data (256). The feedforward predistortion data generator (240) receives the amplitude modulation data (252) and, in response, produces feedforward predistortion data (258). The feedforward adder logic (250) receives the power control error data (256) and the feedforward predistortion data (258) and, in response, produces power control data (260).

Abstract: An apparatus and method to reduce interference in a communication device particularly effective for second-order interference in direct conversion receiver from a co-located transmitter. This is accomplished by characterizing a transfer function of a transmission path from the transmitter to the receiver and applying this transfer function to the baseband signal from the transmitter to provide an estimation of interference to be expected in the received signal. The estimated interference is subtracted from the receiver baseband signal to reduce interference. Adaptive filtering can also be applied to further minimize interference dynamically.

Abstract: An apparatus and method to reduce interference in a communication device particularly effective for second-order interference in direct conversion receiver from a co-located transmitter. This is accomplished by characterizing a transfer function of a transmission path from the transmitter to the receiver and applying this transfer function to the baseband signal from the transmitter to provide an estimation of interference to be expected in the received signal. The estimated interference is subtracted from the receiver baseband signal to reduce interference. Adaptive filtering can also be applied to further minimize interference dynamically.