Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Abstract: Methods and devices for streamlining phase and amplitude calibration and linearization in RF transceiver circuits including a plurality of switchable transmit and receive processing paths is presented. According to one aspect, switchable feedback paths are provided that can selectively feedback a portion of a transmitted RF signal or a test RF signal for use in the calibration. According to another aspect, the switchable feedback paths include combination of switches and couplers to selectively combine feedback from one or more of the switchable feedback paths. According to another aspect, the switchable feedback paths reuse portions of the receive paths of the plurality of switchable transmit and receive processing paths. The switchable feedback paths can be used to provide a combined feedback RF signal based on one or more transmitted RF signals that can be used as a digital pre-distortion feedback for linearization of the one or more transmitted RF signals.

Abstract: A dual feedback topology imparts stability to a multistage linear amplifier, particularly by improving overall amplifier phase margin at higher signal frequencies. With dual feedback, an inner feedback loop is closed around the first amplifier stage, which stage is configured as a current feedback amplifier. A second feedback loop is closed around the overall multistage amplifier. With a current feedback amplifier as the initial stage, the two feedback signals are current-mode signals and thus add to form the combined feedback signal. The frequency responses of the inner and outer feedback loops may be tailored for flat frequency response, or, where desired, may be adjusted to compensate or otherwise flatten overall amplifier frequency response.

Abstract: An error amplifier circuit reduces distortion in an amplified signal by reflecting a feedback signal into the amplified signal using an output transformer. A first amplifier generates a reference signal corresponding to the input signal from which the amplifier output signal is derived. This reference signal represents the desired waveform for the amplified signal. An error sense element generates an error signal based on the difference between the reference and amplified signals. The error sense element preferably imparts high common-mode rejection to the error signal. A second amplifier generates the feedback signal based on amplifying the error signal, and an output transformer generates a compensated amplified signal by coupling the feedback signal into the amplified signal. The output transformer increases the reflected load impedance seen by the error amplifier, thus relieving it from driving the feedback signal into the potentially low load impedance driven by the compensated amplified signal.

Abstract: A dc voltage converter or dc-RF modulation converter includes an inverting {dot over (C)}uk converter circuit operating under hysteretic feedback control. In an exemplary embodiment, the converter further includes a damping circuit to ensure stability over the extended control frequency bandwidth afforded by the hysteretic control. The converter may further include a non pulse-skipping pulse width control circuit, such that the hysteretic controller's switching signal is limited to maximum and minimum pulse widths, which avoids potential saturation issues where transformer isolation is used for switching the {dot over (C)}uk circuit. In an exemplary application, the converter is used as part of a supply modulation amplifier circuit within a wireless base station, which application capitalizes on the extended bandwidth gained through hysteretic control and reduced circuit complexity by generating signal amplification power directly from the −48 VDC supply rail in the base station.

Abstract: A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals; which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.

Abstract: An error amplifier circuit reduces distortion in an amplified signal by reflecting a feedback signal into the amplified signal using an output transformer. A first amplifier generates a reference signal corresponding to the input signal from which the amplifier output signal is derived. This reference signal represents the desired waveform for the amplified signal. An error sense element generates an error signal based on the difference between the reference and amplified signals. The error sense element preferably imparts high common-mode rejection to the error signal. A second amplifier generates the feedback signal based on amplifying the error signal, and an output transformer generates a compensated amplified signal by coupling the feedback signal into the amplified signal. The output transformer increases the reflected load impedance seen by the error amplifier, thus relieving it from driving the feedback signal into the potentially low load impedance driven by the compensated amplified signal.

Abstract: A dual feedback topology imparts stability to a multistage linear amplifier, particularly by improving overall amplifier phase margin at higher signal frequencies. With dual feedback, an inner feedback loop is closed around the first amplifier stage, which stage is configured as a current feedback amplifier. A second feedback loop is closed around the overall multistage amplifier. With a current feedback amplifier as the initial stage, the two feedback signals are current-mode signals and thus add to form the combined feedback signal. The frequency responses of the inner and outer feedback loops may be tailored for flat frequency response, or, where desired, may be adjusted to compensate or otherwise flatten overall amplifier frequency response.

Abstract: A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals, which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.