摘要:
A radio frequency (“RF”) power amplifier circuit as described herein is configured to detect and measure an output load mismatch and to adjust the operating characteristics of the RF power amplifier to reduce output signal distortion. The circuit includes a directional RF signal coupler that obtains a coupled reflected RF signal that is indicative of the output load mismatch. The coupled reflected RF signal is processed to generate one or more bias control signals for the RF power amplifier. In operation, a mismatch condition will result in a measurable coupled reflected RF signal and a corresponding reduction in output power from the RF power amplifier. Ultimately, the output power control mechanism strives to maintain the RF power amplifier within a linear operating range.
摘要:
In an embodiment, a digital pre-distortion apparatus processes an input signal to produce a pre-distorted signal, and processes the pre-distorted signal to produce a feedback signal. The apparatus also rotates an adjustment gain by a gain rotation angle to produce a rotated adjustment gain, where the gain rotation angle is based on a phase difference between the input signal and the feedback signal. The apparatus also applies the rotated adjustment gain to the feedback signal, which may result in rotation of the feedback signal into a target phase region.
摘要:
A device includes a Doherty amplifier having a carrier path and a peaking path. The Doherty amplifier includes a carrier amplifier configured to amplify a signal received from the carrier path and a peaking amplifier configured to amplify a signal received from the peaking path. The device includes a variable impedance coupled to an output of the Doherty amplifier, and a controller configured to set the variable impedance to a first impedance when an output power level of the Doherty amplifier is less than a threshold and to a second impedance when the output power level of the Doherty amplifier is above the threshold.
摘要:
A device includes an amplifier having a first path and a second path and a first variable attenuator connected to the first path. The device includes a controller coupled to the first variable attenuator. The controller is configured to determine a magnitude of an input signal to the amplifier. When the magnitude of the input signal is below a threshold, the controller is configured to set an attenuation of the first variable attenuator to a first attenuation value. When the magnitude of the input signal is above the threshold, the controller is configured to set the attenuation of the first variable attenuator to a second attenuation value. The second attenuation value is less than the first attenuation value.
摘要:
A device includes a Doherty amplifier having a carrier path and a peaking path. The Doherty amplifier includes a carrier amplifier configured to amplify a signal received from the carrier path and a peaking amplifier configured to amplify a signal received from the peaking path. The device includes a variable impedance coupled to an output of the Doherty amplifier, and a controller configured to set the variable impedance to a first impedance when an output power level of the Doherty amplifier is less than a threshold and to a second impedance when the output power level of the Doherty amplifier is above the threshold.
摘要:
A phase shifter with selectable phase shift and comprises a switchable phase shifting element that includes a first and second signal path coupled between an input and an output and providing a, respective, first and second phase shift for a signal coupled through the respective signal paths; a switch circuit for selecting between the first and second signal paths where the first and second signal paths and the switch circuit are configured to equalize the insertion loss for the first and second signal path, the phase shifter further including control circuit for controlling the switch circuit.
摘要:
Variable attenuators and methods of their operation are provided. A variable attenuator includes first and second variable resistance circuits and multiple additional resistors. The first variable resistance circuit has a plurality of current paths coupled in parallel between input and output terminals. A first current path includes two first resistors coupled in series between the input and output terminals, and a switch, which has a channel coupled across one of the two first resistors. The multiple additional resistors include second and third resistors. The second resistor is coupled between the input terminal and an intermediate node. The third resistor is coupled between the output terminal and the intermediate node. The second variable resistance circuit is coupled between the intermediate node and a voltage reference terminal. The level of attenuation provided by the attenuator is controlled by a switch control circuit based on a digital input.
摘要:
In an embodiment, a digital pre-distortion apparatus processes an input signal to produce a pre-distorted signal, and processes the pre-distorted signal to produce a feedback signal. The apparatus also rotates an adjustment gain by a gain rotation angle to produce a rotated adjustment gain, where the gain rotation angle is based on a phase difference between the input signal and the feedback signal. The apparatus also applies the rotated adjustment gain to the feedback signal, which may result in rotation of the feedback signal into a target phase region.
摘要:
A DC-to-DC converter as described herein is suitable for use as a variable voltage supply for an RF power amplifier. The DC-to-DC converter includes a buck converter for providing relatively low voltage and current output, and a linear voltage regulator for providing relatively high voltage and current output. When operating in a buck converter mode, the DC-to-DC converter disables the linear voltage regulator, thus providing efficient low-level operation. When operating in a linear regulator mode, the DC-to-DC converter enables the linear voltage regulator while maintaining at least some current flow through the buck converter; this is accomplished by keeping an output transistor of the buck converter continuously on during the linear regulator mode. The DC-to-DC converter can transition between operating modes in a smooth manner that does not result in discontinuous voltage drops.
摘要:
A power amplifier device having a conductive structure overlying a dielectric layer. The conductive structure has a first conductive structure portion that is substantially electrically isolated from a second conductive structure portion. A first plurality of bond wires couple the first conductive structure portion to an amplifying device, while a second plurality of bond wires couple the second conductive structure portion to the amplifying device.