摘要:
Systems and methods for controlling output power from a power amplifier include a power amplifier configured to generate a power output signal. An output matching circuit is in communication with the power amplifier and is configured to provide an impedance match between the power amplifier and the load. The output matching circuit includes a coupler circuit configured to detect the level of the power output signal. The coupler circuit is further configured to generate a coupler circuit output signal that is proportional to the detected output power level. A feedback control loop circuit is in communication with the coupler circuit and the power amplifier. The feedback control loop circuit is configured to control the power output level based at least in part on the coupler circuit output signal.
摘要:
An apparatus may include a non-linear module, a control module, and a calibration module. The non-linear module produces an output signal from an input signal. The control module selects, upon an occurrence of a calibration condition, a calibration operation from two or more calibration operations. Each of the two or more calibration operations may generate one or more correction values for the non-linear module. Further, each of the calibration operations produces the input signal from a pre-input signal. This selected calibration operation is performed by the calibration module. The two or more calibration operations include a first calibration operation and a second calibration operation. The first calibration operation produces the input signal from the pre-input signal according to a predictive technique. The second calibration operation produces the input signal from the pre-input signal according to a non-predictive technique.
摘要:
Various techniques for biasing a radio frequency digital-to-analog converter are described. In one embodiment, a baseband processor may comprise a plurality of output drivers to generate a plurality of base currents for biasing a radio frequency digital-to-analog converter. The baseband processor may comprise a serial control interface to generate a programming signal for controlling a relationship among the plurality of base currents. Other embodiments are described and claimed.
摘要:
A digital polar transmitter includes a baseband processor configured to receive an input signal and to convert the input signal into a baseband amplitude component and a baseband phase component. The transmitter also includes a phase modulator in communication with the baseband processor. The phase modulator is configured to modulate an RF carrier signal based on the phase component and to generate a phase-modulated RF carrier signal. A power amplifier is provided in communication with the baseband processor and the phase modulator. The power amplifier is configured to amplify the phase-modulated RF carrier signal based on the baseband amplitude component and to generate an amplified RF signal. The transmitter also includes a digital feedback loop in communication with the power amplifier and the baseband processor. The digital feedback loop is configured to detect the amplified RF signal and to provide a digital amplitude feedback signal and a detected phase feedback signal to the baseband processor.
摘要:
An apparatus and method for biasing at least one transistor of a Radio Frequency Digital to Analog Converter (RFDAC). The apparatus including a direct base current injection circuit for injecting a DC current waveform directly into a base terminal of the transistor.
摘要:
An apparatus and method for biasing at least one transistor of a Radio Frequency Digital to Analog Converter (RFDAC). The apparatus including a direct base current injection circuit for injecting a DC current waveform directly into a base terminal of the transistor.
摘要:
An amplifier receives an amplitude signal of a polar modulated signal at a base terminal of a transistor and receives a phase modulated carrier signal of the polar modulated signal at the base terminal of the transistor. The amplifier combines the amplitude signal and the phase modulated signal to produce a full complex waveform at a collector terminal of the transistor.
摘要:
A system and method for modulating and amplifying an input signal are provided in a communication transmitter. The transmitter includes a pre-distortion lookup table containing pre-distortion lookup data. An auto-calibration module is in communication with the pre-distortion lookup table. The auto-calibration module is configured to operate during a closed-loop auto-calibration interval and to calibrate the pre-distortion lookup data to compensate for a non-linearity in the transmitter. A baseband processor is in communication with the pre-distortion lookup table. The baseband processor is configured to receive an input signal and to generate a pre-distorted baseband I/Q signal pair. The pre-distortion is based on the pre-distortion lookup data during an open-loop operational interval. An I/Q modulator is in communication with the baseband processor. The I/Q modulator is configured to modulate an RF carrier signal based on the pre-distorted baseband I/Q signal pair and to generate a pre-distorted, modulated RF carrier signal. A power amplifier is in communication with the baseband processor and the I/Q modulator. The power amplifier is configured to amplify the corrected, modulated RF carrier signal and to generate an amplified RF signal. A digital feedback path in communication with the power amplifier and the baseband processor. The digital feedback path is configured to provide a feedback signal to the baseband processor during the closed-loop auto-calibration interval.
摘要:
A differential analog filter includes a differential input that includes a first input node and a second input node and a differential output that includes a first output node and a second output node. A fully differential amplifier includes a non-inverting input node and an inverting input node coupled to the differential input. The fully differential amplifier includes a non-inverting output node and an inverting output node coupled to the differential output. A first feedback network is coupled between the non-inverting output node and the inverting input node of the fully differential amplifier. A second feedback network is coupled between the inverting output node and the non-inverting input node of the fully differential amplifier.
摘要:
A system and method for modulating and amplifying an input signal are provided in a communication transmitter. The transmitter includes a pre-distortion lookup table containing pre-distortion lookup data. An auto-calibration module is in communication with the pre-distortion lookup table. The auto-calibration module is configured to operate during a closed-loop auto-calibration interval and to calibrate the pre-distortion lookup data to compensate for a non-linearity in the transmitter. The pre-distortion is based on the pre-distortion lookup data and is used during an open-loop operational interval.