Motorola Corporation

Theta-com of California

Bernard Eugene Sigmon

Ronald Gene Myers

Robert Michael Jackson

Frederick Herbert Raab

Shay-Ping T Wang

Kevin M Laird

ShaoWei Wei Pan

Stephen Chih-Hung Ma

James Roger Clark, Ii

Jeffrey G Toler

Lawrence J Schaumacher

Charles T King

Charles V Evans

Lawrence J Schmacher

A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes splitting means ( ), class-G amplifier/modulator ( ), and power amplifier ( ). Three-level class-G amplifier/modulator ( , FIG. ) comprises operational amplifier circuits ( ), three-state selection circuit ( ), switch driver circuit ( ), drive signal routing circuit ( ), power stage circuit ( ), and filter network ( ). Multiple power stages are multiplexed based on the amplitude of the envelope signal.

Method and apparatus for high efficiency power amplification

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 radio frequency signal (FIG. 2, 205) is sampled and the sample is conveyed to a video detector (220). The detected envelope amplitude is sent to an envelope tracking circuit (280), a comparator (230), and an envelope tracking and gate biasing circuit (240). Based on the instantaneous value of the envelope amplitude, the comparator (230) selects one of the available supply voltages (340) via switch drivers (270). The selected one of the available supply voltages (340) is adjusted by the envelope tracking circuit (280) and the resulting voltage output (282) is supplied to the drains of the power amplifiers (390), thus enabling operation near saturation. As the instantaneous value of the envelope amplitude increases, the comparator (230) selects higher supply voltages (340) which increases the voltage conveyed to the power amplifiers (390), thereby increasing their power output. In order to maintain constant gain performance, the envelope tracking and gate biasing circuit (240) modifies the gate bias inversely with the changes the drain voltage.

High efficiency power amplifier circuit with wide dynamic backoff range

A method and apparatus for efficient power amplification over a wide dynamic range and for a number of modulation formats includes a carrier amplifier (30) and a peaking amplifier (40). The carrier amplifier (30) operates with a bias generated by an envelope amplifier (80) which amplifies the envelope of an input signal as generated by an envelope detector (70). The peaking amplifier (40) operates with a fixed bias. The outputs of the carrier amplifier (30) and the peaking amplifier (40) are combined using an impedance transforming network (50). Envelope amplifier (80) can be turned on for high efficiency low power level operation, or it can be turned off for standard Doherty-type operation.

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 class-S modulator (5) receives an input signal (10) having envelope information and pulse-width modulates the input signal (10) using a reference waveform (26) from a waveform generator (25). The envelope becomes a pulse-width modulated signal is level-shifted and amplified through a pre-driver (40). A driver (50) controls switches (60, 70) which drive an output (80) into a low-pass filter (90) wherein the envelope is restored to the amplified signal for driving a power amplifier in a wide-band transceiver.

Wideband class-S modulator and method therefor

A method and apparatus for efficiently amplifying input signals includes multiple amplifiers (20, 30). Each amplifier receives a signal from a power divider (12) where the input signal is split with substantially equal phase. Each amplifier drives a load (40) through a parallel coupled line pair (26, 36). The parallel coupled line pairs are preferably implemented in micro-strip or strip line technology. Each amplifier includes gate bias inputs (24, 34) and drain bias inputs (22, 32). The gate bias inputs can be biased equally and the drain bias inputs can be biased equally, resulting in a parallel, power combined, amplifier configuration. Alternately, the drain bias inputs can be staggered, or the gate bias inputs can be staggered to increase efficiency.

Power amplification apparatus and method therefor

A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes an envelope detector (220), an multi-stage class S modulator (270), and a power amplifier (260). The multi-stage class S modulator (270) includes multiple stages (480), where each stage includes a pair of switching transistors (430, 440) and a capacitor (450). The capacitor (450) supplies the inrush current requirements of the stage (480) so that filtering at the switching frequency is substantially provided within the stage (480). Multiple stages (480) are included on a single semiconductor substrate resulting in higher switching frequencies, higher modulation bandwidths, and lower external filtering requirements.

A three-way phase shifting power coupler (20) processes a primary signal (26) to provide first, second, and third secondary signals (32, 38, and 44) of substantially equal amplitudes. The first and second secondary signals (32 and 38) are phase shifted to be in-phase relative to the primary signal (26). The third secondary signal (44) is phase shifted to produce a quarter-wavelength difference between third secondary signal (44) and the first and second secondary signals (32 and 38). First, second, and third secondary signals (32, 38, and 44) are provided for distribution into a multi-stage amplifier (22). The power coupler (20) is preferably implemented in microstrip.

Phase shifting power coupler with three signals of equal amplitude

An apparatus that includes a logarithm based processor (216) having at least one digital logarithm converter (202) and a power amplifier (208) responsive to the logarithm based processor (216).

Apparatus using a logarithm based processor

A method and apparatus for efficient power amplification of a modulated signal includes an envelope detector (220), an multi-output class S modulator (270), a driver amplifier (250), and a power amplifier (260). The multi-output class S modulator (270) amplifies the envelope of the input signal and generates a primary amplified envelope signal and at least one offset amplified envelope signal. The offset amplified envelope signal is used to modulate the driver amplifier (250), and the primary amplified envelope signal is used to modulate the power amplifier (260).

An apparatus for amplifying a signal that includes a digital processor (12) producing a first digital signal (20) and a second digital signal (22), a pulse width modulator (32) receiving the first digital signal (20) and producing a pulse width modulated signal, an amplitude restoration module (37) responsive to the pulse width modulator (32), the amplitude restoration module (37) producing an amplitude envelope signal, a frequency upconverter (16) receiving the second digital signal (22) and producing a frequency modulated signal, and a power amplifier (18) responsive to the frequency upconverter and the amplitude restoration module (37). The power amplifier receives the frequency modulated signal and the amplitude envelope signal and produces an amplified output signal.

Apparatus for amplifying a signal using a digital processor

A method and apparatus for efficient power amplification with low distortion includes an envelope detector (220), a difference amplifier (130), an envelope amplifier (270), and a power amplifier (260). A feedback path is provided from the output through a second envelope detector (120) to the difference amplifier (130). The feedback circuit operates on the bandwidth of the envelope of the RF signal rather than at the RF bandwidth. An envelope amplifier (270) includes a difference amplifier (272), a pulsewidth modulator (275), a driver (280), switching transistors (285), a low pass filter (290), and a voltage scaler (292). A feedback path within the envelope amplifier reduces the time delay introduced by low pass filter (290). The combined feedback loops work together to reduce distortion and lower intermodulation products.

Method and apparatus for reducing distortion in a power amplifier

A method and apparatus for efficient power amplification with low phase distortion includes an envelope detector (30), a scaling amplifier (40), a driver amplifier (50), and a power amplifier (60). The scaling amplifier (40), in response to the envelope signal from the envelope detector (30), generates a bias signal which causes predistortion in the driver amplifier (50). The predistortion in the driver amplifier (50) compensates for phase distortion in the driver amplifier (50) and the power amplifier (60), resulting in low phase distortion output. An EER-type amplifier (200) with high efficiency utilizes the predistortion of a driver amplifier (250) to compensate for phase distortion in the driver amplifier (250) and a power amplifier (260).

Method and apparatus for compensation of phase distortion in power

A time-delay compensating class-S modulator (4) receives an input signal (10) having RF envelope information and generates a delay error signal (18) from a comparison to an attenuated output signal. The delay error signal (18) is pulse-width modulated using a reference waveform (26) from a waveform generator (25). The envelope becomes a pulse-width modulated signal and is level-shifted and amplified through a pre-driver (40). A driver (50) controls switches (60, 70) which drive an output (80) into a low-pass filter (90) wherein the envelope is restored to the amplified signal for driving a power amplifier in a wide-band transceiver.

Growing community of inventors

Gilbert, AZ, United States of America

Bernard Eugene Sigmon