Abstract: In a first aspect, the invention provides an audio amplifier. A regulator reference signal corresponding to an input audio signal is generated by regulator reference generator. A power signal is generated corresponding to the regulator reference signal by a voltage regulator. A compensation block also uses the input signal, or a delayed version of the input signal to generate a modulation control signal. A modulator generates a modulated signal in response to the modulation control signal. An output stage combines the power signal and the modulation signal to provide an output audio signal corresponding to the input audio signal. The compensation block may be a forward compensation block configured to compensate for characteristics of the regulator reference generator or the voltage regulator or both, and possibly other components of the amplifier. In other embodiments, the compensation block may be part of a feedback compensation loop.

Abstract: A method and apparatus for dynamically compensating for delay mismatch between a supply signal and an input signal of a power amplifier in polar modulation transmitters. One exemplary polar modulation transmitter according to the present invention comprises a power amplifier, a phase modulator, a regulator, a delay tracking circuit, and a delay circuit. The phase modulator derives the amplifier input signal responsive to one or more phase signals, while the regulator derives the amplifier supply signal responsive to an amplitude signal. Based on the amplitude signal and the amplifier supply signal, the delay tracking circuit tracks an observed amplitude path delay. The delay circuit adjusts a path delay associated with the phase signal, responsive to the observed amplitude path delay, to compensate for the delay mismatch.

Abstract: A predistortion linearizer for predistorting a radiofrequency (RF) signal includes a first third-order predistortion linearizer having an input for receiving the RF signal, and a second third-order predistortion linearizer connected in cascade with the first linearizer, whereby fifth order nonlinearities are introduced into a cascaded, predistorted RF output signal. Cascading additional third-order linearizers similarly provides higher-order linearizers.

Abstract: A variable gain amplifying apparatus has an amplifier, one or more first switching elements connected in parallel to the amplifier, and a phase shifter connected in series to the first switching element. The first switching element is enabled if the level of an input signal or an output signal is higher than a predetermined level, and the first switching element is disabled if the level of the input signal or the output signal is equal to or lower than the predetermined level. The amplifier does not operate when the first switching element is enabled, and the amplifier operates when the first switching element is disabled, and the amount of phase shift when the input signal is passed through the amplifier and phase shifter is substantially equal to the amount of phase shift when the input signal is passed through the first switching element.

Abstract: An apparatus and method for operating a feed-forward amplifier in which, after the signal-cancellation and intermodulation-cancellation loops have initially been nulled, the feed-forward amplifier is operated so that both loops are controlled so as to minimize intermodulation at the output of the feed-forward amplifier.

Abstract: The present invention has for its object to provide, in an environment where plural radio systems coexist, a feed forward amplifier for multiple frequency bands, capable of adaptively selecting the frequency band which is used. The feed forward amplifier of the present invention comprises a distortion detection circuit and a distortion elimination circuit and has first and second variable frequency band extractors 25a and 25b provided in series with respective vector adjustment paths 21a and 21b. Also, the feed forward amplifier comprises a frequency band controller which varies the frequency band of variable frequency band extractors 25a and 25b and has been designed, by changing the frequency band of first and second variable frequency band extractors 25a and 25b in response to a frequency switching request from the outside, to be able to adaptively control the frequency band in which distortion is compensated.

Abstract: In an amplifier system that linearizes an amplifier by pre-distorting the input signal prior to amplification, a baseband pre-distortion processor processes the input signal in a digital baseband domain to generate one or more pre-distortion parameters based on the power of the digital baseband input signal. The digital baseband signal is up-converted and D/A-converted into a non-baseband (e.g., IF or RF) signal which is then pre-distorted, e.g., using a phase/gain adjuster or a vector modulator. By generating the pre-distortion parameters at baseband, while pre-distorting the input signal at non-baseband, the amplifier system avoids the cost and inaccuracies associated with analog signal delay and RF power detection of prior-art “all-RF” pre-distortion implementations, while avoiding the wider-bandwidth filtering of prior-art “all-baseband” pre-distortion implementations.

Abstract: A power amplifier circuit (40) that includes an error correction loop (44) having a lower IP3 error correction amplifier (54) than a main power amplifier (46) in a main signal path (48). A first attenuator (52) in the error loop (44) attenuates the RF signal, and provides more attenuation of intermodulation products in the RF signal and about the same attenuation for a main frequency of the RF signal for each dB of attenuation. The error amplifier (54) amplifies the attenuated RF signal from the first attenuator (52). A second attenuator (56) in the error loop (44) attenuates the RF signal from the error correction amplifier (54). A phase shifter (58) phase shifts the RF signal from the second attenuator (56). A coupler (50) couples the amplified RF signal and the phase shifted RF signal to cancel out intermodulation products in the amplified RF signal.

Abstract: A distortion cancellation amplifier is described having a main amplifier and an error amplifier. The main amplifier, in response to an input signal, generates an output signal having an amplified signal component and a distortion signal component. The error amplifier is sized and biased to generate, in response to the same input signal, a distortion signal component that has substantially the same magnitude as the distortion signal component of the main amplifier. The distortion signal component from the error amplifier is subtracted from the output signal of the main amplifier.

Abstract: A delay mismatched feed forward power amplifier is disclosed. Loop 1 includes a main amplifier and is used to derive a carrier cancelled sample of the main amplifier output. Loop 2 includes an error amplifier used to amplify the carrier cancelled signal derived from Loop 1 operation in order to cancel distortion products generated due to the nonlinear nature of the main amplifier. Loop 2 also utilizes a very short Loop 2 delay line. A significant efficiency gain is provided due to reduced output power losses associated with the Loop 2 delay line. Lower output losses also results in lower distortion levels produced by the main amplifier. This, in turn, reduces the size and performance requirements placed on the error amplifier. A smaller and more efficient error amplifier is employed resulting in further amplifier system efficiency improvement. The delay mismatch is compensated by a third control loop, a special adaptive control algorithm or a combination thereof.

Abstract: The invention generally relates to stabilizing an amplifier. In one aspect, a stabilization module that is in electrical communication with the amplifier is provided. The stabilization module includes both an open loop control system and a closed loop control system. The open loop control system is used to modify at least one characteristic of an input signal received by the stabilization module and to pass control to the closed loop control system. The closed loop control system is then used to modify the at least one characteristic of the input signal. The modified input signal is provided to the amplifier.

Abstract: A hybrid distortion compensation method and apparatus that greatly improves the capability to compensate for non-linear distortion due to a high frequency power amplifier over a wideband in strict conditions of smaller size and reduced power consumption. An adaptive pre-distortion section (14) and a feed forward distortion compensation circuit (30) are connected via a D/A converter (20), an A/D converter (28) and the like, and signals of parts of the feed forward distortion compensation circuit (30) are taken out using a switch circuit (SW), fed back to a digital signal processing system, and processed using highly accurate digital signal processing in a control-monitoring section (60). After an adjustment section (51) makes characteristics of two input signals of the feed forward distortion compensation circuit (30) coincide, feed forward distortion compensation is performed. A sequencer (80) controls the components sequentially.

Abstract: Variable gain amplifiers offering high frequency response with improved linearity and reduced power dissipation are provided. An amplifier is disclosed that is constructed from a one-stage topology with multiple signal paths and compensation networks for improved linearity and stable operation. In this amplifier, improved performance is obtained by replacing single transistor components with enhanced active devices which incorporate local negative feedback. One embodiment of the invention is a transconductance enhancement circuit that improves transconductance and input impedance relative to the prior art. A further development is an enhanced active cascode circuit that provides improved linearity. A high frequency bipolar transistor switch is also disclosed that incorporates lateral PNP transistors as high frequency switches with improved OFF-state to ON-state impedance ratio to realize a variable gain function.

Abstract: An electronic class-D amplifier including a pulse width modulator and a servo-loop amplifier characterized in that there is provided a sample and hold element which samples a signal at the sample input when a sample command signal is applied to a control input, and holds the value of the last sampled value of the signal at the sample input when a hold command signal is applied to the control input, and the output of the sample and hold element is connected to a modulation input of the pulse width modulator wherein a negative feedback path connects an output of the output switching stage to an input of the servo-loop amplifier.

Abstract: In a feed-forward power amplifier, a main path amplifies a power level of an input signal to generate a path turning signal, an error path receives the input signal and controls a gain or a phase of a second order intermodulation component in the path turning signal to generate an intermodulation compensation signal, and a first synthesizer generates an output signal responsive to the path turning signal and the intermodulation compensation signal, achieving linearity.

Abstract: In the present technique for power management of a power amplifier, it is first determined (314) whether a counter value corresponds at least in a predetermined way to a counter threshold, and if so, a current status of at least one amplifier bank from a plurality of amplifier banks in a power amplifier is switched (316).

Abstract: In the present technique for power management of a power amplifier, an amplifier bank from a plurality of amplifier banks in a power amplifier that has been switched off for a longest period of time is assessed (826) to provide a lowest amplifier bank. With this lowest amplifier bank, an up-threshold that is associated to the lowest amplifier bank is assessed (828), followed by another assessment (820) of a current power output of the power amplifier. It is next determined (830) whether the current power output corresponds at least in a predetermined way to the up-threshold, and if so, the lowest amplifier bank is accordingly switched on (832).

Abstract: A method of processing an input broadband signal in RF circuitry includes extracting low-frequency components from the input broadband signal, processing the low-frequency components in low-frequency bypass circuitry, and adding the processed low-frequency components to the output of the RF circuitry to produce a combined output signal. Low-frequency bypass amplifier circuitry for bypassing RF circuitry includes a capacitor having a first terminal for receiving an input signal and a second terminal for connecting to an input of the RF circuitry, and a differential amplifier having two inputs respectively connected to the two terminals of the capacitor, and an output connected to an output of the RF circuitry. High-frequency components of the input signal pass through the capacitor and the RF circuitry, and low-frequency components pass through the differential amplifier and are added to the output of the RF circuitry to produce a combined output signal.

Abstract: A feed-forward amplifier having a signal cancellation loop including a cancellation node that includes a gain controller and a phase controller. Each controller provides a discrete tap steering signal and modulates the corresponding tap steering signal with a discrete tracer signal that takes on a preselected sequence of values. The sequence chosen so that the tracer signal is mutually orthogonal to each other tracer signal over a preselected period. A gain and phase adjuster connected to the outputs of the controllers provides a controlled gain change and phase shift in the signal cancellation loop, the magnitude of the gain change and phase shift controlled by the corresponding tap steering signals presented to the gain and phase adjuster by the controllers. A detector, the input of which is connected to the cancellation node and the output of which is connected to the controllers, outputs a measure of the envelope of the signal at the cancellation node.

Abstract: A gain adjuster and a phase adjuster of a distortion generation path are set so that an extracted distortion component becomes small, the extracted component is compared with a reference value. When an upper-frequency distortion component of a pilot signal is larger than the reference value, the gain and phase of a frequency characteristic compensator of the distortion generation path are controlled so that the upper-frequency distortion component of the pilot signal becomes smaller than a value preset in the controller. When a lower-frequency distortion component of the pilot signal is larger than a reference value, the gain and phase of the frequency characteristic compensator of the distortion generation path are controlled so that the lower-frequency distortion component of the pilot signal becomes smaller than a value preset in the controller.

Abstract: There is provided an amplifier that achieves stable distortion compensation without using a pilot signal even when there is a difference in level in the base signal of a multicarrier signal. The amplifier is a feedforward amplifier for amplifying a multifrequency wideband signal without using a pilot signal, and includes an input monitoring section in a signal input stage and an output monitoring section in a signal output stage, whereby for fluctuations in level of the signal from the monitoring sections, when the signal level is decreased to cause a significant decrease in the level of adjacent channel leakage power (ACP) and when the signal level does not decrease to cause a slight increase in ACP level, the controller shifts a set ACP reception frequency to an opposite frequency of the multicarrier signal, thereby achieving stable distortion compensation even when there is a difference in level in the base signal of a multicarrier signal.

Abstract: A linearizer for an amplifier includes an adaptation controller having M monitor signals as inputs. The controller outputs M control settings. The adaptation controller determines M uncorrelated adjustment settings from the M monitor signal inputs. Using the M uncorrelated adjustment settings, the controller adjusts the M control settings for the linearizer.

Abstract: A feed forward amplifier and method of amplification are disclosed. The amplifier output is used to generate a pilot signal via feedback using uncancelled noise in the amplifier output. An automatic level control circuit maintains the pilot signal at a substantially constant level when the detected uncancelled noise in the amplifier output is above a threshold level. The generated pilot signal strength is allowed to vary when the detected uncancelled noise in the amplifier output is below the threshold and disappears automatically when the amplifier is aligned.

Abstract: A dual loop feedforward power amplifier. A dual loop feedforward power amplifier, comprising an input that provides a multicarrier signal; a first feedforward power amplifier; and a second feedforward power amplifier, wherein the first feedforward power amplifier serves as a main amplifier gain block in the second feedforward power amplifier, wherein the first feedforward power amplifier comprises a carrier cancellation loop and a first error amplifier loop, and wherein the second feedforward power amplifier comprises a third loop and a fourth loop that cancel small signal distortions that are not reduced by the first feedforward amplifier.

Abstract: A system reduces non-linear distortions in an output signal of an amplifier stage that is configured according to the feed forward principle. An amplifier stage input signal arrives at a main branch of an amplifier. The output signal of the amplifier, which is distorted in a non-linear manner, arrives at an adder. An output of the adder forms the amplifier stage output signal. The output signal which is distorted in a non-linear manner and the amplifier stage input signal are fed to a secondary branch that comprises an error signal device. The error signal device generates an error signal from the delayed amplifier stage input signal and the output signal of the amplifier, which is distorted in a non-linear manner. The error signal is fed to the adder in order to reduce distortions in the amplifier stage output signal. The error signal device comprises at least one transmission device that is provided with a negative group delay time.

Abstract: A feed forward power amplifier system and method identify active channels across a frequency band to suppress unwanted intermodulation distortion (IMD) products in a communications signal such as a single- or multi-carrier communications signal. A scanning receiver identifies at least one active channel in a frequency band, and identifies at least one portion of the frequency band likely to include IMD products based upon the identified active channel(s). Based upon the identified portion of the frequency band, IMD products are suppressed from the communications signal, e.g., by controlling the magnitude and/or phase of a suppression signal mixed with the communications signal.

Abstract: Provided is a series type Doherty amplifier which includes a first power amplifier and a second power amplifier using a plurality of transformers. The first power amplifier and the second power amplifier are connected in series. The second power amplifier and a first transformer are connected in series. A first path is branched from a junction between the first power amplifier and the second power amplifier and a phase delay device and a second transformer are connected in series. An output port of the second transformer is connected to a junction of a second path of an output port of the second power amplifier. An efficiency of each power amplifier is determined by a ratio of 1:M in size of a final stage of each of the first and second power amplifiers.

Abstract: A fast search algorithm for loop alignment of a feed forward amplifier is disclosed. The algorithm controls a processor that adjusts, digitally, the gain and phase of the loop alignment based on power measurements at the input and output of cancellation combiners, to find the optimal setting. A “non-collinear descent” algorithm is used to search, iteratively, for the minimum within an error surface. For loop alignment, the error surface is defined by the set of measurement points comprising the alignment settings and the associated cancellation residuals. For the case of first loop alignment, the cancellation residual is measured using the ratio of two power detectors located at the input and after the cancellation (error) combiner. For second loop alignment, cancellation is estimated using the residual pilot power detected at the output of the amplifier. The preferred alignment method uses three successive measurements to estimate the gradient direction with respect to gain and phase shifter settings.

Abstract: Briefly, in accordance with one embodiment of the invention, a portable communication device comprises an amplifier having an input signal and an output signal. The amplitude of the input signal may be compared to the amplitude of the output signal and an appropriate analog signal may be generated to adjust the ratio of the input signal to the output signal.

Abstract: Amplifying signals includes receiving an input signal. The input signal is amplified at a quadrature coupled amplifier to generate an amplified signal. The input signal is compared with the amplified signal to generate an error signal. The error signal is amplified at the quadrature coupled amplifier to generate an amplified error signal. The amplified error signal is compared with the amplified signal to generate an output signal.

Abstract: An amplification system and method is provided that employs a digital cross-cancellation technique which provides a separate digital signal to be input to a separate DAC to generate a cancellation signal. The cancellation signal is added to the output of the amplifier to produce a final signal with substantially reduced distortion and/or out-of-band emissions. The cancellation signal can be pre-computed or derived by generating an inverted version of the wanted signal, and combining it with a portion of the output signal to determine the error or unwanted portion of the output signal. This error signal is then combined with a delayed version of the output signal.

Abstract: A delay mismatched feed forward amplifier system employing a control system and method using floors and penalties is disclosed. The disclosed control system and method allows the second loop phase adjuster setting to be offset in a repeatable and controlled manner. Applying floors and penalties to offset the steady-state phase adjuster setting modifies the conventional pilot cancellation approach. In the conventional case, pilot cancellation has a distinct minimum that corresponds to the desired adjustment setting. In the disclosed approach, the measured pilot cancellation is clipped to a lower bound or floor to produce a set of equal valued minimum control results. The floor is selected to place a desired phase offset to the phase adjuster at the edge of minimum floor. To ensure that the correct phase adjuster offset is selected from the set of equal valued minimum control results, a control direction based penalty is added.

Abstract: A method for aligning a feed forward radio frequency power amplifier includes applying a radio frequency signal to the feed forward radio frequency power amplifier and monitoring a radio frequency signal from the feed forward radio frequency power amplifier, without opening a break point of the feed forward radio frequency amplifier.

Abstract: A multi-band feed-forward amplifier is formed by: a dividing part for dividing and applying an input signal containing signals of multiple frequency bands to a linear signal path and N vector adjustment paths of a distortion detecting circuit; frequency band signal extractors provided in the N vector adjustment paths, respectively, for extracting signals of N frequency bands; N vector adjusters for adjusting the vectors of the output signals from the respective frequency band signal extractors; a main amplifier for amplifying the output signals from the N vector adjusters; a combining/dividing part for combining the amplified signals and the signal from the linear signal path of the distortion detecting circuit and for dividing and applying the combined output to a linear signal path and N distortion injection paths of a distortion cancelling circuit; frequency band signal extractors provided in the N distortion injection paths, respectively, for extracting the signals of the N frequency bands; vector adjuste

Abstract: A predistortion linearizer may include a digital signal processor (DSP) for modeling a nonlinear characteristic of a high power amplifier (HPA) on a real time basis; a distortion signal generator for generating a distortion signal by using the signal modeled by the DSP; and a main path unit for combining the output signal of the HPA and the distortion signal of the distortion signal generator and transmitting an input signal without a distortion component. Since the nonlinear characteristic of the power amplifier is modeled on a real time basis to remove the distortion component contained in the output signal of the power amplifier, the nonlinear characteristic of the power amplifier is improved, and thus, an efficiency of the power amplifier can be maximized.

Abstract: RF phase distortion circuits and methods for controllably phase distorting an RF signal based on amplitude of the RF signal. An MOS device is provided having a body of a first conductivity type and at least one region of a second conductivity type in the body, with a conductive layer over at least part of the body and the region of the second conductivity type and insulated therefrom. The MOS device may be coupled into a phase distortion circuit individually or in back-to-back pairs and biased to invert the body under the conductive layer for small signal amplitudes and not for large signal amplitudes, or to not invert the body under the conductive layer for small signal amplitudes and to invert the body under the conductive layer for large signal amplitudes. Various embodiments are disclosed.

Abstract: Base station transmitter signals are combined more effectively through the use of anti-phase pilots between pairs of transmission paths. At the combiner, the pilots will cancel when the amplitude, phase, and delay of the two transmission paths entering the combiner are matched. As a result, the pilots will not appear at the output except when the alignment is incorrect. By detecting the residual pilot at the combiner output, the information is used to adjust the alignment of one of the transmission paths to match the other. The adjustments to the amplitude, phase, and delay are performed on the input signal, after the pilot injection.

Abstract: A feed-forward operational amplifier including a dedicated summer circuit for summing a signal generated by a first amplifier stage of a feed-forward amplifier and a signal received from an external source to generate a sum signal and a second amplifier stage coupled to the summer circuit and receiving the sum signal. The second amplifier stage realizes a pole-zero doublet to decrease a unity gain frequency of the feed-forward operational amplifier.

Abstract: An RF power amplifier having reduced memory effects is disclosed. This is achieved by a novel design of the DC supply feed network to achieve low impedance across video frequencies, whilst maintaining the correct RF output matching. One or more transmission zeros are provided in the bias circuit transfer function, which are positioned in the video bandwidth so as to provide low and relatively constant impedance across the video bandwidth. Also, a parallel DC feed line may be employed to reduce impedance across the video bandwidth. The reduction in memory effects allows improved performance of predistortion linearization techniques and an implementation in a feed forward amplifier employing predistortion linearization is also disclosed.

Abstract: A radio frequency (RF) amplifier system includes an RF power amplifier having an input and an output, and a typical gain of 1000 or more between the input and the output. An adaptive feedback channel is coupled between the input and the output of the RF power amplifier. The adaptive feedback channel receives as inputs audio signals for modulation of the input of the RF power amplifier, a frequency command word indicative of a desired frequency and phase of the RF amplifier system, and a control word indicative of a desired power level of the output of the RF power amplifier and of a mode of operation of the RF amplifier system. In response to the inputs, the adaptive feedback channel provides as an output a degenerative feedback signal to the input of the RF power amplifier.

Abstract: The present invention relates to an arrangement and a method for amplifying high frequency RF signals having amplitude and phase variations. The objective problem of the present invention is to provide an efficient power amplifier for amplifying high frequency RF signals. The object is achieved by introducing a Signal Conditioning Device (SCD) that converts baseband signals SI and SQ into tri-states signals STI, STQ. The tri-states signals STI, STQ are time multiplexed, which results in that a single power amplifier can be used to amplify the signal on the In-phase (I) channel and the signal on the Quadrature (Q) channel. Hence, the present invention does not require a power combiner.

Abstract: This apparatus comprises a high-frequency signal amplifier formed by a main power stage (30) which has an input for an incoming signal, an output for the amplified signal and a gain control (37). This amplifier also comprises a first comparator (49) for producing a signal that has a distortion level between the incoming signal and the amplified signal, and a differential element (45) for removing the distortion signal from the amplified signal. Moreover, for the distortion signal to be of the same level as the distortions caused by the main power stage, a secondary amplifier stage (53) is added which is inserted in a canceling loop so that the power of its output signal is constant. This loop is constituted by a measuring circuit for measuring the output power of said auxiliary amplifier stage by a comparing circuit for comparing this power to a reference value (61) and by a processing circuit (58) for influencing said gain control (37). Application: Amplifier for mobile radio telephones.

Abstract: A circuit is provided, having a feed forward linear power amplifier configured with two or more error correction loops (225–235, 255–265). Each of the error correction loops includes a band pass filter (237, 257). Each of the band pass filters (237, 257) is tuned to a different frequency range. A controllable frequency oscillator (220) can be coupled to an input of the error correction loops. A controller sweeps the frequency of the controllable frequency oscillator over the frequency range corresponding to each of the band pass filters (237, 257).

Abstract: The present invention relates to a Multi Carrier Power Amplifier, MPCA, comprising a number of parallel Multi Carrier Power Amplifiers, each comprising an amplification loop and an error cancellation loop, said amplification loop comprising at least a first gain and phase control network and a first amplifier and a second amplifier. The MPCA comprises an external loop comprising a second Spread Spectrum Signal added to said each first loop.

Abstract: The invention concerns a method for maintaining an optimal operating point of an LDMOS device stable, said LDMOS device producing an output signal including an error signal component. The method comprises separating said error signal component from the output signal of said LDMOS device and using said error signal component for controlling the gate-to-source bias voltage, or Vgs, of said LDMOS device to maintain the optimal operating point of the LDMOS device stable.

Abstract: The invention generally relates to stabilizing an amplifier. In one aspect, a stabilization module that is in electrical communication with the amplifier is provided. The stabilization module includes both an open loop control system and a closed loop control system. The open loop control system is used to modify at least one characteristic of an input signal received by the stabilization module and to pass control to the closed loop control system. The closed loop control system is then used to modify the at least one characteristic of the input signal. The modified input signal is provided to the amplifier.

Abstract: Variable gain amplifiers offering high frequency response with improved linearity and reduced power dissipation are provided. An amplifier is disclosed that is constructed from a one-stage topology with multiple signal paths and compensation networks for improved linearity and stable operation. In this amplifier, improved performance is obtained by replacing single transistor components with enhanced active devices which incorporate local negative feedback. One embodiment of the invention is a transconductance enhancement circuit that improves transconductance and input impedance relative to the prior art. A further development is an enhanced active cascode circuit that provides improved linearity. A high frequency bipolar transistor switch is also disclosed that incorporates lateral PNP transistors as high frequency switches with improved OFF-state to ON-state impedance ratio to realize a variable gain function.

Abstract: A noiseless amplifier circuit has an amplifier, a first circuit that isolates amplifier generated noise and provides the desired gain, a second circuit that cancels the amplifier generated noise from the output signal from the amplifier, a closed loop feedback third circuit that modulates the input signal to the amplifier to compensate for amplifier generated noise, and first and second controls that keep phase and amplitude balanced at a combiner in the first and second circuits, respectively. An oscillator circuit and a mixer circuit incorporate the noiseless amplifier circuits.

Abstract: An amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction. The correction signal that removes signal distortion and OOB emissions associated with the peak reduction can be calculated or electronically derived. The correction signal can be combined with the peak reduced signal prior to or after amplification of the peak reduced input signal.

Abstract: The present invention provides a novel feed forward amplifier (“FFA”) and a pilot tone generator-receiver therefor. In an embodiment of the invention, the feed forward amplifier only requires a single oscillator to operate both the pilot tone generator and pilot tone receiver used in conjunction with the amplifier circuitry of the FFA. In another embodiment of the invention, a method is provided of generating and detecting a pilot tone from a single oscillating signal.