An active filter comprising an operational amplifier, and a controller configured to control the bandwidth of the operational amplifier based on a filter cutoff frequency setting and/or a noise performance setting.

A method and system for power amplifier tuning based on an automobile audio bus (A2B) interface including determining a plurality of tuning paths and a plurality of tuning parameters of one or more power amplifiers; determining data volumes of the plurality of tuning parameters according to the type(s) of the one or more power amplifiers; determining a data volume for each tuning path according to the data volumes of the plurality of tuning parameters; allocating the number of A2B channels to each tuning path according to the data volume determined for each tuning path; calculating a tuning speed for each tuning, path according to the number of A2B channels allocated to each tuning path; and allocating the calculated tuning speed for each tuning path to the one or more power amplifiers through the A2B interface.

A method and system for power amplifier tuning based on an automobile audio bus (A2B) interface including determining a plurality of tuning paths and a plurality of tuning parameters of one or more power amplifiers; determining data volumes of the plurality of tuning parameters according to the type(s) of the one or more power amplifiers; determining a data volume for each tuning path according to the data volumes of the plurality of tuning parameters; allocating the number of A2B channels to each tuning path according to the data volume determined for each tuning path; calculating a tuning speed for each tuning, path according to the number of A2B channels allocated to each tuning path; and allocating the calculated tuning speed for each tuning path to the one or more power amplifiers through the A2B interface.

An equalizer system includes at least one equalizer configured to equalize an input signal to generate an equalized input signal; a limiting amplifier coupled to the at least one equalizer, and configured to amplify the equalized input signal to a saturated level to generate an output signal; and a control circuit coupled to the at least one equalizer and the limiting amplifier, and configured to generate at least one control signal to the at least one equalizer according to the equalized input signal to adjust a peak gain of the at least one equalizer, wherein the peak gain of the at least one equalizer is at a Nyquist frequency.

An equalizer system includes at least one equalizer configured to equalize an input signal to generate an equalized input signal; a limiting amplifier coupled to the at least one equalizer, and configured to amplify the equalized input signal to a saturated level to generate an output signal; and a control circuit coupled to the at least one equalizer and the limiting amplifier, and configured to generate at least one control signal to the at least one equalizer according to the equalized input signal to adjust a peak gain of the at least one equalizer, wherein the peak gain of the at least one equalizer is at a Nyquist frequency.

A method and system for power amplifier tuning based on an automobile audio bus (A2B) interface including determining a plurality of tuning paths and a plurality of tuning parameters of one or more power amplifiers; determining data volumes of the plurality of tuning parameters according to the type(s) of the one or more power amplifiers; determining a data volume for each tuning path according to the data volumes of the plurality of tuning parameters; allocating the number of A2B channels to each tuning path according to the data volume determined for each tuning path; calculating a tuning speed for each tuning, path according to the number of A2B channels allocated to each tuning path; and allocating the calculated tuning speed for each tuning path to the one or more power amplifiers through the A2B interface.

A method and system for power amplifier tuning based on an automobile audio bus (A2B) interface including determining a plurality of tuning paths and a plurality of tuning parameters of one or more power amplifiers; determining data volumes of the plurality of tuning parameters according to the type(s) of the one or more power amplifiers; determining a data volume for each tuning path according to the data volumes of the plurality of tuning parameters; allocating the number of A2B channels to each tuning path according to the data volume determined for each tuning path; calculating a tuning speed for each tuning, path according to the number of A2B channels allocated to each tuning path; and allocating the calculated tuning speed for each tuning path to the one or more power amplifiers through the A2B interface.

A power amplifier system can include a power amplifier that provides amplification to a radio frequency signal associated with a first frequency band and outputs an amplified radio frequency signal. An acoustic wave bandpass filter such as a surface acoustic wave or bulk acoustic wave bandpass filter is arranged in a feedback configuration with respect to the power amplifier. The filter can pass through a portion of the amplified radio frequency signal corresponding to a second frequency to provide negative feedback to the power amplifier, resulting in a reduction in an amount of gain from the power amplifier within the second frequency band.

A power amplifier system can include a power amplifier that provides amplification to a radio frequency signal associated with a first frequency band and outputs an amplified radio frequency signal. An acoustic wave bandpass filter such as a surface acoustic wave or bulk acoustic wave bandpass filter is arranged in a feedback configuration with respect to the power amplifier. The filter can pass through a portion of the amplified radio frequency signal corresponding to a second frequency to provide negative feedback to the power amplifier, resulting in a reduction in an amount of gain from the power amplifier within the second frequency band.

A power amplifier system can be configured to provide amplification to a radio frequency signal associated with a first frequency band and to output an amplified radio frequency signal. The system can include a bandpass filter arranged in a feedback loop with respect to the power amplifier and configured to pass through a portion of the amplified radio frequency signal corresponding to a second frequency band. A first shifter can be positioned in the feedback loop, and an output of the feedback loop can provide negative feedback to an input of the power amplifier.