Powerwave Technologies, Inc.

Do B Shin

Richard D Posner

Charles R Gentzler

Kwang Kim

Bill Vassilakis

Thomas Quang Ha

Stefan Klein

Sandip Patel

Gregory French

Wayne Roberts

The invention relates to a low cost feed forward RF power amplifier arrangement for amplifying an RF input signal using a main power amplifier operating as a class A/B amplifier. The method and apparatus modify the input signal to the main amplifier to compensate for the distortion added by the main power amplifier. The circuit provides for injecting a delayed version of the input signal, through a fixed gain-phase circuity, at a point whereby the resulting signal is amplified by the error amplifier of the second loop. A digitally controlled processor iteratively modifies various phase and gain controls to adjust the output of the amplifier. Different gain and phase control lines are iteratively updated at different rates.

Low cost, pilotless, feed forward compensation for a power amplifier

An apparatus and method reduce out-of-band frequency components of an amplified, multichannel RF signal able to have at least two frequency bandwidth limited signal channels, each channel having a respective carrier frequency which is not known in advance. The channels can, for example, be dedicated to CDMA signals. Each channel of the amplified RF signal has both in-band frequency components and out-of-band frequency components. The apparatus and method feature a network for amplifying an input signal for producing the amplified RF signal, the network having adjustable electrical characteristics, and a control system connected to the network for locating a frequency within the bandwidth of one of the channels of the amplified RF signal and for detecting energy in the out-of-band frequency components for the one located channel for producing control signals relating to the energy in that one channel. As a result of adjusting the electrical characteristics of the network, the energy in the out-of-band frequency components for that channel, and all other channels of interest, can be reduced.

Multichannel amplification system using mask detection

A method and apparatus for reducing out-of-band frequency components of an RF amplified input signal, the amplified signal having both in-band frequency components and out-of-band frequency components, employ a feedforward network in which a microprocessor can sweep a frequency generator output connected to a mixer, the other input of the mixer being the amplified output, to find the carrier frequency of the input signal, and thereafter modify or control the feedforward circuit to reduce out-of-band frequency component energies in a particular manner. For example, gain and phase of a variable gain-phase network in a feedforward circuit structure can be modified for reducing the out-of-band frequency component energy.

Feedforward amplification system having mask detection compensation

A method and apparatus for reducing out-of-band frequency components of an RF signal having a carrier frequency which is not known in advance employ a control signal to vary adjustable bias parameters of the circuit. In particular embodiments, the RF signal is generated from a MOSFET power amplifier, which introduces distortion components into its output signal. Bias parameters of the MOSFET amplifier can be varied to reduce out-of-band frequency components, that is, out-of-band distortion. In addition, other elements of the network can be controlled by varying bias parameters, for example, a predistorter.

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Laguna Hills, CA, United States of America

Do B Shin