1
John F Sevic, Richard J Camarillo: Efficient parallel-stage power amplifier. QUALCOMM Incorporated, Russell B Miller, Brian S Edmonston, Roger W Martin, February 16, 1999: US05872481 (189 worldwide citation)

An amplifier circuit for providing an amplified signal in response to an input signal. The amplifier circuit includes an input network for applying the input signal to a selected at least one of a plurality of amplifier stages. An output network is provided for coupling the amplified signal from the ...


2
Tim Forrester: Systems and methods for controlling output power in a communication device. Kyocera Wireless, March 23, 2004: US06710651 (184 worldwide citation)

A wireless communication device comprises a power amplifier configured to amplify a power level of a transmit signal to a required transmit power level and a transmission line coupled with the power amplifier. The transmission line is configured to convey the amplified transmit signal. The wireless ...


3
Heikki Mattila, Jorma Matero, Hannu Pakonen: Dual mode amplifier with bias control. Nokia Mobile Phones, Perman & Green, July 11, 1995: US05432473 (183 worldwide citation)

A dual mode transmitter with bias control is described wherein an RF signal from a system modulator is fed to a gain control circuit, which can be either a voltage controlled amplifier or attenuator. The ultimate transmitter output power level depends on the attenuation/gain of the gain control circ ...


4
Veikko R Saari: Amplifier with controlled gain. Bell Telephone Laboratories Incorporated, Volker R Ulbrich, April 3, 1984: US04441080 (160 worldwide citation)

Amplifier gain is varied in response to a control voltage by a switched capacitor variable transconductance feedback network. First and second capacitors are connected in series between the input and the output of an operational amplifier. The input side of the first capacitor is switched by a first ...


5
Gerald M Cooper: Method for automatically adjusting audio response for improved intelligibility. Ericsson, Nixon & Vanderhye PC, August 4, 1998: US05790671 (156 worldwide citation)

Intelligibility of received speech in a radio receiver is improved by automatically adjusting audio response in accordance with ambient noise levels. When high ambient noise is present, the relative gain of the higher audio frequencies is increased at the expense of low frequency response. In this i ...


6
Marc D Liang, Krishna Narayanan, John L Kurtz: Voice activated microscope. The Montefiore Hospital Association of Western Pennsylvania, Harry B Keck, January 29, 1991: US04989253 (155 worldwide citation)

A microscope has a voice activated control system which permits precise location of the microscope and precise focusing by means of voice commands uttered by the microscope operator. When the microscope is in a movement mode, the movement is terminated by any sound exceeding a pre-established acoust ...


7
Robert E Myer: Amplifier with modulated resistor gain control. American Telephone and Telegraph Company AT&T Bell Laboratories, Jack S Cubert, October 10, 1989: US04873492 (151 worldwide citation)

An automatic gain control circuit for an amplifier operating over a prescribed frequency range detects the output level of the amplifier; and couples a repeated predetermined waveform occurring at a rate greater than the reciprocal of twice the upper frequency of the prescribed frequency range to th ...


8
Bernard J Arntz, William A Nitz, Josef Ocenasek: Method and apparatus for reducing the peak-to-average power in multi-carrier RF communication systems. AT&T Bell Laboratories, Alfred G Steinmetz, April 12, 1994: US05302914 (148 worldwide citation)

Therefore a method and apparatus for controlling a linear amplifier processing a plurality of carrier signals of a multi channel carrier system alters the phases of one or more sources of the multi-channel signals in response to a detected peak envelope power or of a peak to average power ratio at r ...


9
James Edward Mitzlaff: Bias circuit for a power amplifier. Motorola, May 26, 1998: US05757229 (145 worldwide citation)

A method for amplifying an RF input signal using a power amplifier (105, 107 or 205, 207) comprises the steps of dividing or quadrature splitting (103) the RF input signal into an in-phase signal and a quadrature phase signal. A carrier amplifier bias input (111, 211) signal is varied relative to th ...


10
Frank P Helms: Automatic volume control to compensate for ambient noise variations. Advanced Micro Devices, Haynes and Boone L, September 9, 1997: US05666426 (136 worldwide citation)

A system and method for automatically adjusting the volume of an audio system to compensate for variations in ambient noise. The system includes a microphone for monitoring the ambient audio environment which includes output of the audio system plus environmental noise. The system also includes proc ...