A technology is described for adjusting repeater gain based on user equipment need. A repeater can be configured to receive a downlink signal strength indicator value of a user equipment (UE) via a wireless connection of the UE with the repeater. The repeater can be further configured to select a threshold value for the downlink signal strength indicator value. The repeater can be further configured to reduce or bypass a downlink repeater gain level when the downlink signal strength indicator value is greater than the threshold value.

An active gain control circuit includes a voltage divider having a variable resistance configured to attenuate a rectified input line voltage to produce a reference signal, a filter circuit configured to extract a DC-level reference voltage from the reference signal, and an operational amplifier configured to receive the DC-level reference voltage and a comparison voltage, and to generate a gate control signal based on a difference between the comparison voltage and the DC-level reference voltage, wherein a resistance of the voltage divider is controlled by the gate control signal.

Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, receiving an auxiliary attenuation signal from an auxiliary attenuation source, determining a threshold power level based on a value of the auxiliary attenuation signal, determining an output power level of the audio signal exceeds the threshold power level, combining the audio signal with the auxiliary attenuation signal from the auxiliary attenuation source and a compressed attenuation signal from the feedback compressor circuit to create a combination signal, and generating an audio output signal of the feedback compressor circuit based on the combination signal.

A system configured to perform adaptive feedback reduction, such as howling suppression, to prevent feedback from occurring when two devices are acoustically coupled during a communication session. To reduce feedback between the acoustically coupled devices, a device monitors input audio data from a microphone and determines whether feedback is present in individual frequency subbands. For example, the device determines an expected value for a first subband using neighboring subbands (e.g., averaging subbands surrounding the first subband) and compares the expected value to an actual value for the first subband. If the actual value is noticeably higher than the expected value, the device determines that feedback is present in the first subband and attenuates the first subband. If the feedback is not present, the device passes the first subband without attenuation.

Various methods and circuital arrangements for protection of an RF amplifier are presented. According to one aspect, the RF amplifier is part of switchable RF paths that include at least one path with one or more attenuators that can be used during normal operation to define different modes of operation of the at least one path. An RF level detector monitors a level of an RF signal during operation of any one of the switchable RF paths and forces the RF signal through the at least one path with one or more attenuators while controlling the attenuators to provide an attenuation of the RF signal according to a desired level of protection at an input and/or output of the RF amplifier.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, receiving an auxiliary attenuation signal from an auxiliary attenuation source, determining a threshold power level based on a value of the auxiliary attenuation signal, determining an output power level of the audio signal exceeds the threshold power level, combining the audio signal with the auxiliary attenuation signal from the auxiliary attenuation source and a compressed attenuation signal from the feedback compressor circuit to create a combination signal, and generating an audio output signal of the feedback compressor circuit based on the combination signal.

A variable-gain amplifier includes two amplification and attenuation branches, and first and a second resistive elements that are coupled between the two branches. Each branch includes a voltage follower stage and a configurable amplification stage. The voltage follower stages are intended to receive a differential signal and are configured to deliver, via the first resistive element, an intermediate differential current signal. The amplification stages are intended to receive the intermediate differential current signal and a digital control word, and are configured to deliver, via the second resistive element, an output differential voltage signal depending on the value of the digital control word.

At least one embodiment relates to a radio-frequency (RF) power amplifier system for amplifying a first RF signal. The RF power amplifier system includes a RF power amplifier being configured to amplify a second RF signal. The RF power amplifier system also includes a control loop for controlling a power level of the second RF signal. The control loop includes a RF output power determining unit for determining a power level of the amplified second RF signal. The control loop also includes a gain determining unit for determining an actual large signal gain based on the determined power level of the amplified second RF signal and a power level of the second RF signal. Further, the control loop includes an attenuator for attenuating the first RF signal and for providing the attenuated first RF signal to the RF power amplifier as the second RF signal.

Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.