Abstract: A circuit for providing a bias signal for a power amplifier includes a first input, a second input and an output. The first input is configured to receive an input signal to be amplified by the power amplifier. The second input is configured to receive the amplified input signal. The output is configured to provide the bias signal.

Abstract: A distortion estimation apparatus for estimating distortion includes a feedback element, a nonlinearity determiner, and a distortion simulator. The feedback element provides a feedback signal derived from a distorted output signal of the distorting element. A signal processing quality of the feedback element is lower than an associated signal property of the distorted output signal. The nonlinearity determiner receives the feedback signal and an input signal to the distorting element or a signal derived from the input signal. The nonlinearity determiner determines an estimated transmission characteristic of the distorting element by relating signal properties of the feedback signal and the input signal or the signal derived from the input signal. The distortion simulator estimates the distortion caused by the distorting element based on the input signal or the signal derived from the input signal and the estimated transmission characteristic.

Abstract: One embodiment of the present invention relates to a method and apparatus are provided herein for reducing the power consumption of a transmission chain while maintaining an acceptable figure of merit (e.g., linearity). In one embodiment, an adaptive biasing element is configured to perform adaptive biasing to reduce current consumption of a transmission chain by adjusting the operating point of one or more transmission chain elements (e.g., power amplifier, mixer, etc.). However, since adaptive biasing may reduce the linearity of a transmitted signal, its use is limited by the degradation of figure of merit caused by the introduced non-linearities. Accordingly, a pre-distortion element may be configured to perform adaptive digital pre-distortion (DPD) on a transmission chain input signal to account for non-linearities generated through the adaptive biasing, therefore allowing the adaptive biasing to further reduce the current consumption while maintaining an acceptable figure of merit.

Abstract: An apparatus for providing a linearity information associated with an amplifier includes an operating state determinator and an evaluator. The operating state determinator is configured to obtain information describing a gain of the amplifier for at least one bias condition of the amplifier. The evaluator is configured to obtain the linearity information based on both the information describing the gain of the amplifier and information about the at least one bias condition of the amplifier using a gain-bias characteristic of the amplifier. A bias circuit including the apparatus for providing the linearity information is also disclosed.

Abstract: One embodiment of the present invention relates to a method for transistor matching. The power transmitter comprises a first, second, and third amplification path. The paths are selectively activated and deactivated to output a received signal with high efficiency and linearity. The first amplification path is configured to receive a first signal and output a first amplified signal to a first port of a output power combiner when activated and provide an impedance that results in a high reflection factor when deactivated. The second amplification path is configured to receive a second signal with 90° phase shift with respect to the first signal and output a second amplified signal to a second port of the combiner when activated and provide an impedance that results in a high reflection factor when deactivated.

Abstract: One embodiment of the present invention relates to a method for transistor matching. The power transmitter comprises a first, second, and third amplification path. The paths are selectively activated and deactivated to output a received signal with high efficiency and linearity. The first amplification path is configured to receive a first signal and output a first amplified signal to a first port of a output power combiner when activated and provide an impedance that results in a high reflection factor when deactivated. The second amplification path is configured to receive a second signal with 90° phase shift with respect to the first signal and output a second amplified signal to a second port of the combiner when activated and provide an impedance that results in a high reflection factor when deactivated.