A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output, include a feedback network coupled between the amplifier output and an input of the analog integrator, and a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, force the amplifier output to a fixed known duty cycle, measure an analog signal generated at the output of the analog integrator in response to forcing the input of the analog integrator to the fixed value, determine an offset of the switched mode amplifier system based on the analog signal, and correct for the offset.

A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output, include a feedback network coupled between the amplifier output and an input of the analog integrator, and a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, force the amplifier output to a fixed known duty cycle, measure an analog signal generated at the output of the analog integrator in response to forcing the input of the analog integrator to the fixed value, determine an offset of the switched mode amplifier system based on the analog signal, and correct for the offset.

A switching amplifier comprises a controller, configured to receive an input signal and a reference signal, and to generate a control signal according to the input signal and the reference signal; a pulse-width modulation (PWM) modulator, coupled to the controller, configured to generate a PWM signal according to the input signal and the control signal; a power management unit, coupled to the controller, configured to receive a power supply and the control signal, and to provide an adaptive supply voltage according to the power supply and the control signal; and a switching power stage, coupled to the power management unit and the PWM modulator, configured to generate an output signal according to the PWM signal and the adaptive supply voltage.

A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output and include a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, force the amplifier output to a fixed known duty cycle, measure an analog signal generated at the output of the analog integrator in response to forcing the input of the analog integrator to the fixed value, determine an offset of the switched mode amplifier system based on the analog signal, and correct for the offset.

A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output and include a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, force the amplifier output to a fixed known duty cycle, measure an analog signal generated at the output of the analog integrator in response to forcing the input of the analog integrator to the fixed value, determine an offset of the switched mode amplifier system based on the analog signal, and correct for the offset.

A switched mode amplifier system may include a switched mode amplifier having an amplifier input coupled to an output of an analog integrator and an amplifier output, include a feedback network coupled between the amplifier output and an input of the analog integrator, include a loop filter configured to generate a digital loop filter output, include a quantizer configured to generate a pulse-width modulated representation of the digital loop filter output; and include a calibration system. The calibration system may be configured to force the input of the analog integrator to a fixed known input value, low-pass filter the pulse-width modulated representation of the digital loop filter output generated by the quantizer to generate a filtered quantizer output signal, determine an offset of the switched mode amplifier system based on the filtered quantizer output signal, and correct for the offset.

A variable gain low noise amplifier (LNA) and a method for controlling a gain of the variable gain LNA are provided. The variable gain LNA may include a first transistor, a first degeneration inductor, a second transistor and a second degeneration inductor, wherein the first degeneration inductor is coupled to a source terminal of the first transistor, and the second degeneration inductor is coupled to a source terminal of the second transistor. Gate terminals of the first transistor and the second transistor are configured to receive an input signal. The first transistor and the first degeneration inductor belong to a first branch of the variable gain LNA, and the second transistor and the second degeneration inductor belong to a second branch of the variable gain LNA. More particularly, a gain of the variable gain LNA is determined by controlling whether to turn off the second branch.

Embodiments disclosed herein describe a wireless power receiver including a synchronous transistor rectifier using a Class-E or a Class-F amplifier. The wireless power receiver includes at least one radio frequency (RF) antenna configured to generate an alternating current (AC) waveform from received RF waves. The wireless power receiver further includes a power line configured to carry a first signal based on the AC current generated by the least one RF antenna, and a tap-line coupled to the power line, the tap-line being configured to carry a second signal. The second signal is based on the AC current generated by the least one RF antenna and distinct from the first signal. The wireless power receiver also includes a transistor coupled to at least the power line and the tap-line. The transistor is configured to provide a direct current (DC) waveform to a load based on the first and second signals.

A power supply for supplying a power to a heating mechanism used for heating a measurement target that emits a measurement signal includes an input device configured to output an input signal that reflects a control signal in a differentiable periodic waveform having a frequency of 1 kHz or less. The power supply includes a switching amplifier configured to amplify the input signal from the input device and output the amplified signal.

A power supply for supplying a power to a heating mechanism used for heating a measurement target that emits a measurement signal includes an input device configured to output an input signal that reflects a control signal in a differentiable periodic waveform having a frequency of 1 kHz or less. The power supply includes a switching amplifier configured to amplify the input signal from the input device and output the amplified signal.