Other

Motorola Corporation

Frederick Herbert Raab

Bernard Eugene Sigmon

Ronald Gene Myers

James Roger Clark, Ii

Kenneth V Buer

A circuit and method for electronically tuning an RF power amplifier. The output filter includes at least one electronically variable reactance. The electronically tuned power amplifier may be tuned rapidly to a selected frequency, to a selected impedance, or to produce a selected output amplitude. An optional controller translates frequency, impedance, or modulation inputs into tuning signals. High-efficiency, wideband amplitude modulation is produced by varying the amplifier load impedance along preferred loci.

Electronically tuned power amplifier

A method and a circuit for power amplification over a wide frequency range based upon the use of minimum-rating filters or matching networks, negative-component signal processing, and single or multiple amplifiers. The filters and matching networks are preferably designed to minimize the required ratings of the amplifier(s) driving them. The signal processor or generator preferably uses negative components to produces a driving signal that is compensated for the ripple in the filter, matching network, and load. The outputs of multiple amplifiers optimized for different frequency ranges can be combined into a single load with flat frequency response, resistive loads presented to the amplifiers, and no inherent power loss in the combining network.

Wideband, minimum-rating filters and multicouplers for power amplifiers

A method and a circuit for high-efficiency linear RF-power amplification over a wide range of amplitudes from zero to peak output includes a final RF-power amplifier operating at or near saturation, an RF driver amplifier, a high-level amplitude modulator for the final amplifier, preferably a high-level amplitude modulator for the driver amplifier, and a means for determining the supply-voltage input to the final amplifier and for controlling the amplitude of the drive. The means for determining the supply-voltage input and for controlling the amplitude acts so that the final amplifier drive varies from a minimum level to peak as the desired transmitter output varies from zero to peak. The transmitter is preferably of the envelope-elimination-and-restoration type or the envelope-tracking type.

Power- conserving drive-modulation method for envelope-elimination-and-restoration (EER) transmitters

Technique for wideband operation of power amplifiers

A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes an envelope detector (,), an adaptive split band modulator (,), and a power amplifier (,). The adaptive split band modulator (,) amplifies the low frequency components using a class S modulator (,), and amplifies the high frequency components using a class B amplifier (,). The power supply of the class B amplifier (,) is adaptively modified as a function of the amplitude of the signal that it amplifies. In this manner, the class B amplifier (,) operates at a higher efficiency.

Method and apparatus for high efficiency wideband power amplification

A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes an envelope detector (220), an adaptive split band modulator (270), and a power amplifier (260). The adaptive split band modulator (270) amplifies the low frequency components using a class S modulator (760), and amplifies the high frequency components using a class B amplifier (750). The power supply of the class B amplifier (750) is adaptively modified as a function of the amplitude of the signal that it amplifies. In this manner, the class B amplifier (750) operates at a higher efficiency.

A method and apparatus for efficient power amplification of a high dynamic range signal includes an envelope detector (220), a multi-range modulator (270), and a power amplifier (260). The multi-range modulator (270) efficiently amplifies the envelope of the input signal by selecting a power source as a function of the amplitude of the input signal. Multi-range modulator (200) produces a pulsewidth modulated signal with a duty cycle and an amplitude. When the amplitude of the input signal rises above a reference, the duty cycle and the amplitude are modified so as to keep the multi-range modulator in an operating region of high efficiency.

Method and apparatus for high efficiency high dynamic range power

A method and apparatus for efficient power amplification with low distortion includes a surface acoustic wave delay line (210), an envelope detector (220), an envelope amplifier (270), and a power amplifier (260). An envelope amplifier (270) includes a pulsewidth modulator (275), a driver (280), switching transistors (285), and a low pass filter (290). The surface acoustic wave delay line (210) functions to balance the delay of the envelope and the carrier of the signal to be amplified. The use of the surface acoustic wave delay line (210) obviates the need for a separate delay line in the phase path of the amplifier.

Growing community of inventors

Colchester, VT, United States of America

Frederick Herbert Raab