A method of operating a radio receiver device comprises receiving a plurality of signals with a plurality of corresponding frequencies; applying respective gains to each of the plurality of signals; and storing the gain applied to each signal and its corresponding frequency. The method comprises subsequently receiving a further signal with a further frequency; and applying a further gain to the further signal. The further gain is determined using at least one of the stored gains according to a difference between the further frequency and at least one of the plurality of corresponding frequencies.

A clamping circuit that may be used to provide efficient and effective voltage clamping in an RF front end. The clamping circuit comprises two series coupled signal path switches and a bypass switch coupled in parallel with the series coupled signal path switches. A diode is coupled from a point between the series coupled signal path switches to a reference potential. In addition, an output selection switch within an RF front end has integrated voltage clamping to more effectively clamp the output voltage from the RF front end. Additional output clamping circuits can be used at various places along a direct gain signal path, along an attenuated gain path and along a bypass path.

A transimpedance amplifier (TIA) for converting an input current at an input node into an output voltage at an output node, the TIA comprising: a first amplifier stage having a first input coupled to the input node and a first output; a feedback path between the first output and the first input; a second amplifier stage in the feedback path having a second input, the second input coupled to the first output of the first amplifier stage; a feedback resistor in the feedback path coupled between an output of the second amplifier stage and first input of the first amplifier stage; and an output stage, comprising: a load resistor coupled between a reference voltage node and a T-coil, the T-coil comprising first and second inductors coupled in series at an inductor node, the T-coil coupled between the first output and the load resistor, the inductor node coupled to the output node of the TIA.

This application is generally related to methods for improving performance in a system. One of the methods may include a step of determining whether absorbed power in a system meets a predetermined threshold. The absorbed power may be based upon first and second Walsh codes transmitted to each of first and second gain and phase modulators in the system. The first Walsh code may be orthogonal to the second Walsh code. A first set of the first and second Walsh codes may be inverted with respect to a second set of the first and second Walsh codes. The method may also include a step of modulating the absorbed power in view of the determination. The method may further include a step of transmitting feedback based upon the modulated power to the first and second gain and phase modulators.

A symbol power tracking amplification system including: a modem to generate data and symbol tracking signals; a symbol tracking modulator including a control circuit, first and second voltage supply circuits and a switch circuit, the control circuit generates first and second voltage level control signals in response to the symbol tracking signal, the first voltage supply circuit generates a first output voltage in response to the first voltage level control signal, the second voltage supply circuit generates a second output voltage in response to the second voltage level control signal and the switch circuit outputs the first or second output voltages as a supply voltage in response to a switch control signal; an RF block to generate an RF signal based on the data signal from the modem; and a power amplifier to adjust a power level of the RF signal based on the supply voltage.

A symbol power tracking amplification system including: a modem to generate data and symbol tracking signals; a symbol tracking modulator including a control circuit, first and second voltage supply circuits and a switch circuit, the control circuit generates first and second voltage level control signals in response to the symbol tracking signal, the first voltage supply circuit generates a first output voltage in response to the first voltage level control signal, the second voltage supply circuit generates a second output voltage in response to the second voltage level control signal and the switch circuit outputs the first or second output voltages as a supply voltage in response to a switch control signal; an RF block to generate an RF signal based on the data signal from the modem; and a power amplifier to adjust a power level of the RF signal based on the supply voltage.

A decoder for a wireless charging transmitter and a wireless charging transmitter using the same are provided in the present invention. In order to adapt the wide range of the received signal from the wireless charging receiver, which usually results in the error of the decode, the feedback circuit of the wireless charging transmitter is changed, so that the signal in a certain swing is amplified by an original gain, and the signal out of the certain swing is amplified by a limited gain. Therefore, the amplified signal is able to show the characteristic of the original received signal. Thus, the accuracy of decoding is increased.

A decoder for a wireless charging transmitter and a wireless charging transmitter using the same are provided in the present invention. In order to adapt the wide range of the received signal from the wireless charging receiver, which usually results in the error of the decode, the feedback circuit of the wireless charging transmitter is changed, so that the signal in a certain swing is amplified by an original gain, and the signal out of the certain swing is amplified by a limited gain. Therefore, the amplified signal is able to show the characteristic of the original received signal. Thus, the accuracy of decoding is increased.

Aspects of the subject technology relate to a device including a microphone, a filter and a processor. The filter receives an audio signal including ambient noise and a voice of a user of the device from the microphone. At least a portion of ambient noise is filtered from the audio signal. The processor determines a level of the ambient noise in the received audio signal and dynamically adjusts a gain applied to the filtered audio signal based on the level of the ambient noise.

The present application relates to the field of audio technology, and provides a method, a device, and an apparatus for playing audio, and a computer-readable storage medium. The method for playing audio includes: obtaining an ambient atmospheric pressure value and audio data to be played; obtaining multiple target frequency points contained in the audio data to be played when the ambient atmospheric pressure value meets a preset condition, and determining equal-loudness multiples corresponding to the target frequency points according to the ambient atmospheric pressure value and a preset calibration atmospheric pressure value; and sending the audio data to be played and the equal-loudness multiples of the target frequency points to a power amplifying module, such that the power amplifying module amplifies the audio data to be played according to the equal-loudness multiples corresponding to the target frequency points.