1
Yasunori Suzuki, Toshio Nojima: Feed-forward amplifier. NTT Docomo, Oblon Spivak McClelland Maier & Neustadt P C, May 21, 2002: US06392483 (76 worldwide citation)

In a feed-forward amplifier a signal power dynamic range compressing circuit for compressing the power dynamic range of the input signal to the feed-forward amplifier is provided in a distortion detecting loop at the input side of a main amplifier, and the output backoff of the main amplifier is red ...


2
Katsuyoshi Sugimoto: Feed-forward amplifier and method of compensating non-linear distortion in the same. NEC Corporation, Ostrolenk Faber Gerb & Soffen, May 15, 2001: US06232838 (72 worldwide citation)

A first vector modulator is inserted in the input route of an amplifier to vary the input signal of the amplifier. A second vector amplifier is inserted in the second signal route to vary the input signal of the second signal route. A controller controls the first vector modulator to minimize the di ...


3
Armando C Cova, Emil J Crescenzi Jr, Augustin P Chang, Stephen J Foley: High linearity multicarrier RF amplifier. Spectrian Corporation, Allen Dyer Doppelt Milbrath & Gilchrist P A, January 7, 2003: US06504428 (71 worldwide citation)

A hybrid multicarrier RF power amplifier linearization architecture combines ACT and feed-forward amplifier stages to achieve high output distortion rejection and enhanced amplifier linearity. A carrier cancellation loop is coupled with a main RF power amplifier stage having parallel RF power amplif ...


4
Wentian Zhang, Bryan Todd Irons, Mark Ian Van Horn: Method and apparatus for reduction of distortion in a feed forward amplifier. Motorola, Steven A May, March 2, 2004: US06700441 (68 worldwide citation)

A feed forward amplifier performs a carrier cancellation tuning process separate from an IM reduction tuning process, wherein the carrier cancellation tuning process is performed without reference modulations that are utilized to modulate a feed forward amplifier input signal during the IM reduction ...


5
James K Cavers: Adaptive feedforward linearizer for RF power amplifiers. Simon Fraser University, Oyen Wiggs Green & Mutala, February 6, 1996: US05489875 (53 worldwide citation)

A feed forward amplifier circuit for amplifying an input signal to produce an amplified replica thereof. A first splitter splits the input signal into first and second signal cancellation branches. The first signal cancellation branch contains an amplifier and a first "delay, gain and phase adjuster ...


6
Krister I Ripstrand, Thorsten Nygren: Linear amplifier control. Telefonaktiebolaget L M Ericsson, Burns Doane Swecker & Mathis, January 31, 1995: US05386198 (52 worldwide citation)

A method and apparatus for controlling a feed-forward compensated power amplifier system is disclosed which uses a spread spectrum technique to cover a control signal or signals and injects a composite signal at a suitable point into the feed-forward amplifier system to reduce distortion. The amount ...


7
Shoichi Narahashi, Toshio Nojima, Makoto Maeta, Kazuaki Murota: Feed-forward amplifier. Nippon Telegraph and Telephone Corporation, Pollock Vande Sande and Priddy, November 24, 1992: US05166634 (51 worldwide citation)

In a feed-forward amplifier which has an error detection circuit for detecting a nonlinear distortion component of a main amplifier and an error rejection circuit for amplifying the detected distortion component by an auxiliary amplifier and injecting it into the main amplifier to cancel an error co ...


8
Patrick A Quinn: Feed-forward amplifier. Tektronix, George T Noe, March 27, 1979: US04146844 (45 worldwide citation)

A high-precision amplifier employs a feed-forward technique to provide a first order correction of amplifier distortion. A second amplifier is utilized to sense the base-to-emitter distortion of a main amplifier and develop an error output which is injected into an output node to provide cancellatio ...


9
Robert E Myer: Low-distortion feed-forward amplifier. AT&T Bell Laboratories, Jason P DeMont, April 19, 1994: US05304945 (44 worldwide citation)

A low-distortion, high-power, feed-forward amplifier is disclosed which is particularly well-suited for cellular radio applications. An illustrative embodiment comprises a main amplifier and a pair of correction amplifiers, which each are used to eliminate different distortion products introduced by ...


10
Derek L Tattersall Jr: Feed forward amplifier network with frequency swept pilot tone. Motorola, Val Jean F Hillman, July 14, 1992: US05130663 (40 worldwide citation)

Briefly described the present invention is a feed forward amplifier network employing a frequency swept pilot tone signal in order to reduce the distortion generated by the network's power amplifier. A frequency swept pilot tone, generated for example by a variable frequency oscillator, is injected ...