Tropian, Inc.

Panasonic Corporation

Other

Matsushita Electric Industrial Co., Ltd.

Proxim Corporation

Cushman Electronics, Inc.

Mccune, Earl W.

Earl W McCune

Wendell B Sander

Kenneth R Cioffi

Nigel J Tolson

Wayne S Lee

Ronald A Meck

Lawrence M Burns

Stephan Vincent Schell

Richard W D Booth

Gary Lang Do

Bojan Silic

A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds. For most airfoils, a slightly negative angle of attack results in zero lift, so this simple approach has a ready fail-safe condition. This fail-safe condition is operable up to very high wind speeds, eliminating any need to provide for turbine overspeed control. The same teachings are equally applicable to water turbines and other types of turbines.

Wind turbine having flow-aligned blades

An AC/DC converter that converts an AC input voltage Vin to a DC output voltage comprises an inductor, a capacitor selectively coupled to the inductor, a plurality of switches, and a controller. The controller configures the plurality of switches, inductor, and capacitor to operate as a buck converter during times when Vin&#x3e;Vout and to operate as an inverting buck converter during times when Vin&#x3c;&#x2212;Vout. The controller modulates the duty cycles of the plurality of switches to regulate the DC output voltage Vout to the desired, constant output level.

AC/DC power conversion methods and apparatus

A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds.

A relationship is established between measurable characteristics of the DC power input to a power amplifier and the RF output power level. A power circuit is configured to measure the input supply current to the power amplifier and to utilize the relationship between the input supply current and the applied input supply voltage to the output power level, thereby normalizing the output power of an amplified communication signal.

VSWR normalizing envelope modulator

A transmission apparatus has two modes of power amplifier operation, in which modeis inherently accurate, modeis inherently less accurate, and measurement of a power amplifier output from modeis used to correct a power amplifier output in mode. Modemay be a compressed mode and modemay be a non-compressed mode. The apparatus may include a power controller that provides overlapping scaling factor sets for modesandand controls transmission power using the scaling factor sets. Upon a mode transition, the controller uses the overlapping scaling factors and changes the scaling factor set for the mode of a destination of the transition based on actual measurement representative of transmission power, for example, by carrying out power alignment loop operations. A cellular mobile device may include such transmission apparatus. A polar modulation transmitter is also disclosed.

Transmission power controller

In an embodiment of the invention, a system provides for efficient polar and linear signal modulation. The system has a controller coupled to a voltage converter and a modulator. The system also has an amplifier coupled to the voltage converter and the phase modulator. The controller is for receiving an input and providing a polar signal. The voltage converter is for receiving the polar signal, receiving a voltage input, and providing a power signal. The amplifier is for amplifying the modulated signal based on the power signal. The voltage converter provides a feedback signal to the controller, and the controller adjusts a scale of modulation, such as a peak of the modulation signal, based on the feedback signal, such that the output power and the amplification by the amplifier are based on the feedback signal.

Envelope modulator saturation detection using a DC-DC converter

The present invention, generally speaking, uses multiple selectable power supply paths, a saturation detector, or combinations of the same to achieve efficient power supply processing. In one aspect of the invention, a power supply processing circuit includes a first switched converter stage and a second linear stage. Depending on the power supply desired, the first stage may be bypassed to avoid conversion losses. In another aspect of the invention, a saturation detector is used to control the first stage such that the second stage operates efficiently just short of saturation, thereby avoiding distortion.

Power supply processing for power amplifiers

A hybrid modulator apparatus includes a modulator that amplitude modulates a power supply signal. A correction circuit coupled in parallel with the modulator reduces errors caused by the modulator. In one embodiment the modulator includes a digital pulse-width modulator (PWM) and a buck converter. The K most significant bits (MSBs) of N-bit input digital words are used by the digital PWM and a buck converter to generate an amplitude modulated power supply signal having a plurality of quantized voltage levels. The remaining N&#x2212;K bits of each N-bit words may be used to dither the input drive to the PMW, to produce an error signal at the output of the modulator representing quantization errors caused by only applying the K MSBs to the PWM. The correction circuit compares the error signal to a signal formed form all N bits of the N-bit words in reducing the quantization errors.

Enhanced hybrid class-S modulator

A polar-based modulator includes an amplitude signal generator operating at a set gain and a command module that selects an appropriate one parameter lookup table based on an identification of the current network communication system. The command module receives a digital representation of the desired amplitude and using the received digital amplitude and selected parameter lookup table determines control commands used by a scalar to appropriately modulate an amplitude modulated signal output from the amplitude signal generator. Use of the parameter lookup table and command module in the digital realm eliminates the complexities of comparable functionality in the analog realm. Further, operating the amplitude signal generator at a set gain and scaling the output eliminates the complexities associated with generating an appropriately amplified signal within the amplitude signal generator and improves the overall efficiency for generating such an amplitude modulated signal.

Method of configuring a polar-based modulator using a parameter look-up table

The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC-DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation. Amplitude modulation may be achieved by directly or effectively varying the operating voltage on the power amplifier while simultaneously achieving high efficiency in the conversion of primary DC power to the amplitude modulated output signal. High efficiency is enhanced by allowing the switch-mode DC-to-DC converter to also vary its output voltage such that the voltage drop across the linear regulator is kept at a low and relatively constant level. Time-division multiple access (TDMA) bursting capability may be combined with efficient amplitude modulation, with control of these functions being combined. In addition, the variation of average output power level in accordance with commands from a communications system may also be combined within the same structure.

High-efficiency modulating RF amplifier

The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired modulation. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC&#x2014;DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation wave-form. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation. Amplitude modulation may be achieved by directly or effectively varying the operating voltage on the power amplifier while simultaneously achieving high efficiency in the conversion of primary DC power to the amplitude modulated output signal. High efficiency is enhanced by allowing the switch-mode DC-to-DC converter to also vary its output voltage such that the voltage drop across the linear regulator is kept at a low and relatively constant level. Time-division multiple access (TDMA) bursting capability may be combined with efficient amplitude modulation, with control of these functions being combined. In addition, the variation of average output power level in accordance with commands from a communications system may also be combined within the same structure.

The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., hard-limiting or switch-mode) power amplifier. In one embodiment, the invention exploits the recognition that, for a constant-resistance circuit, power is equal to the square of the voltage across the circuit divided by the resistance of the circuit. In the case of certain switch mode amplifiers, such as Class E and Class F amplifiers, as well as saturated linear amplifiers, the amplifier may reasonably be regarded as having a constant resistance with varying power supply. In an exemplary embodiment, the supply voltage is controlled using a combination of two stages, a switch-mode converter stage that accomplishes gross power level control and a subsequent linear regulator stage that accomplishes more precise power envelope control, e.g., burst control. Control circuitry for the amplifier is simplified by combining control signals for power amplifier ramp-up transition, power level during a TDMA burst, and ramp-down transition, into a single control signal, and by eliminating feedback control (which also eliminates errors in the feedback control of output power due to the use of detecting diodes). Output noise from the variable output switch-mode voltage converter stage is filtered using the linear regulator stage that accomplishes burst control, further increasing circuit efficiency. Energy efficiency during ramp-up to the desired output power, during the burst at all output power levels, and during ramp-down from the transmitted power, is maximized. Reasonable expected efficiencies for the switch-mode converter stage and the linear regulator stage are 90% and 80%, respectively. A high-efficiency switch-mode amplifier may have an efficiency on the order of 80%, enabling an overall efficiency of greater than 50% to be achieved, comparing very favorably with current efficiencies of about 10%.

High-efficiency amplifier output level and burst control

The present invention, generally speaking, provides for high-efficiency power control of a high-efficiency (e.g., bard-limiting or switch-mode) power amplifier in such a manner as to achieve a desired control or modulation. Unlike the prior art, feedback is not required. That is, the amplifier may be controlled without continuous or frequent feedback adjustment. In one embodiment, the spread between a maximum frequency of the desired modulation and the operating frequency of a switch-mode DC-DC converter is reduced by following the switch-mode converter with an active linear regulator. The linear regulator is designed so as to control the operating voltage of the power amplifier with sufficient bandwidth to faithfully reproduce the desired amplitude modulation waveform. The linear regulator is further designed to reject variations on its input voltage even while the output voltage is changed in response to an applied control signal. This rejection will occur even though the variations on the input voltage are of commensurate or even lower frequency than that of the controlled output variation. Amplitude modulation may be achieved by directly or effectively varying the operating voltage on the power amplifier while simultaneously achieving high efficiency in the conversion of primary DC power to the amplitude modulated output signal. High efficiency is enhanced by allowing the switch-mode DC-to-DC converter to also vary its output voltage such that the voltage drop across the linear regulator is kept at a low and relatively constant level. Time-division multiple access (TDMA) bursting capability may be combined with efficient amplitude modulation, with control of these functions being combined. In addition, the variation of average output power level in accordance with commands from a communications system may also be combined within the same structure.

Growing community of inventors

Santa Clara, CA, United States of America

Earl W McCune