Disclosed herein is a DC offset cancellation circuit. The DC offset cancellation circuit includes a DC feedback unit configured to vary a DC feedback (DCFB) bandwidth to add at least one mid-bandwidth to the DCFB bandwidth and to provide a delay time in each case in order to reduce the DC droop error that occurs in switching from the high bandwidth (BW) to the mid-BW or from the mid-BW mode to the low BW mode, such that stable settling is ensured.

At least some embodiments are directed to a receiver system that comprises a first oscillation module configured to provide oscillating signals of differing frequencies and a second oscillation module configured to provide other oscillating signals of the differing frequencies. The second oscillation module is configured to produce less noise than the first oscillation module. A controller is coupled to the first and second oscillation modules and configured to selectively activate and deactivate each of the first and second oscillation modules based on signal strengths of primary signals received via a wireless medium and based on signal strengths of interference signals received via the wireless medium.

A device includes a variable gain amplifier, a voltage shifter, a variable gain amplifier half replica module, and an analog to digital converter. The variable gain amplifier includes an input terminal to receive an input signal, an output terminal to provide a first output signal that is biased based on a first common-mode voltage reference. The voltage shifter circuit includes first and second input terminals, and an output terminal to provide, to the analog to digital converter, a third output signal that is biased based on a second common-mode voltage reference. The variable gain amplifier half replica module includes an output terminal coupled to the second input terminal of the voltage shifter circuit, the variable gain amplifier half replica module to control the third output signal of the voltage shifter circuit based on the first common-mode voltage reference and the second common-mode voltage reference.

In connection with an RF communication system, exemplary aspects may involve a method and apparatus for use in a communication system in which a RF receiver may be detecting and processing a first signal in an RF channel. Thereafter, a second received signal may be detected, with the second received signal being assessed, by receiver circuitry, as stronger than the first received signal. In response to the assessment of the second received signal being stronger than the first received signal, the RF receiver circuitry may adjust the gain or signal amplification circuitry for continuing to process the second, stronger, received signal in place of the first, weaker, received signal.

A wireless receiver includes an antenna receiving a right-handed circularly polarized (RHCP) signal and a left-handed circularly polarized (LHCP) signal, a first amplifier and a second amplifier coupled to the antenna, an intermediate summer coupled to the first and second amplifiers and providing a first intermediate signal, an intermediate subtractor coupled to the first and second amplifiers and providing a second intermediate signal. The wireless receiver also includes a V-signal summer providing a V-component output based on a sum of the first intermediate signal and the second intermediate signal, and an H-signal subtractor providing an H-component output based on a difference between the first intermediate signal and the second intermediate signal. The wireless receiver is configured to provide the V-component output and the H-component output without using a phase shifter.

This automatic gain control circuit is provided with a variable gain amplifier for amplifying a received signal, has a small circuit size, and makes it possible to reduce the effect of superimposed external noise input within the frequency bandwidth of a received signal. The automatic gain control circuit supplies the output of the variable gain amplifier to an analog/digital converter and comprises: a frequency selection circuit that is connected to the output of the analog/digital converter and that selects a signal within the frequency bandwidth of a received signal, said signal having a narrower bandwidth than the frequency bandwidth; and a control signal generation circuit that generates a control signal for the variable gain amplifier on the basis of the strength of the signal selected by the frequency selection circuit.

Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may support multi-subscriber identity module (SIM) operation in dual SIM dual active (DSDA) deployments. In some aspects, the UE may receive, via an antenna of the UE, a first signal associated with a first network subscription on a first receive path of the antenna and a second signal associated with a second network subscription on a second receive path of the antenna. The UE may determine a signal strength for each of the first signal and the second signal, determine a first gain for the first receive path and a gain for a low noise amplifier (LNA) coupled with the antenna based on the signal strength of the first signal, and determine a gain for the second receive path based on the signal strength of the second signal and the gain of the LNA.

In some implementations, an automatic gain control (AGC) circuit comprises: a pre-divider circuit operable to pre-divide an input signal according to a pre-divider circuit setting and output a pre-divided signal; a pre-amplifier operable to pre-amplify the pre-divided signal and output a pre-amplified signal; a post-divider circuit operable to post-divide the pre-amplified signal according to a post-divider circuit setting; an analog-to-digital converter (ADC) operable to generate a digital data stream from the post-divided signal; logic operable to sample the digital data stream; determine a pre-divider circuit setting and a post-divider circuit setting based on the sampled data stream; set the pre-divider circuit and the post-divider circuit based on the determined settings; and generate a received signal strength value based on the pre-divider circuit setting and the post-divider circuit setting.

The present invention describes an amplifier adjusting device for an amplifier element which is adjustable as a function of amplification factor and is coupled to a frequency domain selecting element for adjusting at least to frequency domains. The amplifier adjusting device includes a memory in which at least two amplification factors may be stored, the at least two amplification factors being assigned to the two at least two frequency domains, an amplification factor adjusting element configured to select, depending on a current frequency domain, a corresponding amplification factor from the memory in order to adjust the adjustable amplifier element, and an amplification factor estimator configured to correct, based on an analysis of a signal amplified by means of the adjustable amplifier element in accordance with the selected amplification factor, the selected amplification factor and store the corrected amplification factor in the memory.

A distributed antenna system (DAS) and method are disclosed. The system includes at least one RIM associated with a remote unit. The RIMs and the remote units (RU) are configured for transmitting and receiving test signal over at least one narrow band of frequencies. The system includes a plurality of signal generators associated with a signal path, each signal generator configured for generating a test signal over the at least one narrow band of frequencies; a controller configured to generate a test signal for the signal path; and, an equalizer for adjusting gain for the signal path according to at least one of the narrow band of frequencies.