Abstract:
A method and system for adaptive self-biasing of a power amplifier are disclosed. A current (Ids) at an output of the power amplifier is measured, the current being a sum of a quiescent current (Idq) and a current arising from an RF signal applied to an input of the power amplifier. An output signal power (Pout) of the power amplifier is measured. A target value of Ids corresponding to the measured value of Pout is either calculated or obtained from a look-up table. The measured current Ids is compared to the target value of Ids to determine an error value. An input biasing voltage (Vgs) of the power amplifier is adjusted based on the error value to achieve a measured value of Ids that is equal to the target value of Ids corresponding to the measured value of Pout.
Abstract:
A method for controlling pulsed power that includes measuring a first pulse of power from a power amplifier to obtain data. The method also includes generating a first signal to adjust a second pulse of delivered power, the first signal correlated to the data to minimize a power difference between a power set point and a substantially stable portion of the second pulse. The method also includes generating a second signal to adjust the second pulse of delivered power, the second signal correlated to the data to minimize an amplitude difference between a peak of the second pulse and the substantially stable portion of the second pulse.
Abstract:
A self-configurable amplifier and method of amplification, including an RF signal level detector having an input connected to an RF signal, and an output configured to produce a control signal responsive to a power level of the RF signal. The control signal is supplied to a parametric adjustment circuit that includes an input connected to the control signal, and an output configured to provide a negative feedback responsive to the control signal. The negative feedback is supplied to an RF amplifier that includes an input forming an input of the self-configurable amplifier, an output forming an output of the self-configurable amplifier, and a control port connected to the output of the parametric adjustment circuit, such that one or more parameters of the RF amplifier is responsive to the negative feedback.
Abstract:
Designs and techniques associated with power amplifiers for amplifying RF signals to provide variable power amplification and improved linearity in various RF amplification circuits, including power amplifiers operated under the power back-off conditions.
Abstract:
A power detector comprises a pair of transistor amplifier elements (Q 1 , Q 2 ) having respective control terminals for receiving with opposite polarities (V ip , V in ) a radio/mm-wave frequency signal whose power is to be detected. Respective alternately-conductive parallel amplifier paths are controlled by the control terminals. A low pass filter and current mirror (M 1 , 222, 224, M 2 ) is responsive to the combined currents flowing in the parallel amplifier paths for producing a low pass filtered signal. A detector output stage (Q 3 , Q 4 , M 3 , M 4 ) is responsive to the low pass filtered signal. Each of the pair of amplifier elements (Q 1 , Q 2 ) includes a respective impedance (R 1 , R 2 ) through which flows current from the respective amplifier path and current from the respective control terminal.
Abstract:
An RF transmitter (30) includes an RF power amplifier (32) for which the power input bias voltage (40) and signal input bias voltage (80) are controlled within feedback loops. A peak detector (44) generates a lowered-spectrum, peak-tracking signal (34) that follows the largest amplitude peaks of a wide bandwidth communication signal (16) but exhibits a lower bandwidth. This signal (34) is scaled in response to the operation of a drain bias tracking loop (146) then used to control a switching power supply (36) that generates the power input bias voltage. The tracking loop (146) is responsive to out-of-band power detected in a portion of the amplified RF communication signal (16"). A ratio of out-of-band power (128) to in-band power (126) is manipulated in the tracking loop (146) so that the power input bias voltage is modulated in a way that holds the out-of-band power at a desired predetermined level.
Abstract:
Circuits, methods, and systems are provided for opening a primary feedback loop (207) in a transmitter. An auxiliary feedback loop (208) can be closed when the primary feedback loop (207) is opened, and a controller (209) can match a gain of the primary feedback loop (207) to another gain in the transmitter.
Abstract:
A transmitter circuit (200, 400, 510) and method reduces amplitude modulation distortion in an amplifier (210). The transmitter circuit (200, 400, 510) includes a power control error data generator (230), a feedforward predistortion data generator (240), feedforward adder logic (250) and the amplifier (210). The power control error data generator (230) receives amplitude modulation data (252) and an RF coupled output signal (254) and, in response, produces power control error data (256). The feedforward predistortion data generator (240) receives the amplitude modulation data (252) and, in response, produces feedforward predistortion data (258). The feedforward adder logic (250) receives the power control error data (256) and the feedforward predistortion data (258) and, in response, produces power control data (260). The amplifier (210) receives the power control data (260) and an RF input signal (261) and, in response, produces an RF output signal (262), such that the power control data (260) reduces amplitude modulation distortion in the RF output signal (262).