A wireless repeater is disclosed. The wireless repeater can include a first front-end booster. The wireless repeater can include a second front-end booster. The wireless repeater can include a signal combiner device. The wireless repeater can include a main booster. The wireless repeater can include a coaxial cable communicatively coupled to the signal combiner device. The wireless repeater can include a control unit. The control unit can adjust an adjustable gain of the first front-end booster, an adjustable gain of the second front-end booster, or an adjustable gain of the main booster based on an expected signal loss of at least one of the signal combiner device or the coaxial cable.

In one embodiment a differential amplifier arrangement includes a first input configured to receive a first input signal, a second input configured to receive a second input signal, a first output configured to provide a first output signal, a second output configured to provide a second output signal, a common mode loop configured to regulate an output common mode of the differential amplifier arrangement depending on a difference between a common mode reference signal and an average of the first and the second output signal, and a differential mode loop configured to regulate a differential mode output of the differential amplifier arrangement depending on a difference between a difference between the first and the second input signal and a difference between the first and the second output signal. Therein the difference between the first and the second output signal is substantially constant.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

In some implementations, a radiofrequency down converter comprises an input port to receive a radiofrequency input signal, and the down converter includes a first bandpass filter configured to filter the input signal. The down converter includes a mixer stage coupled to the bandpass filter, the mixer stage being configured to generate a mixer output signal by processing the filtered input signal using a gain adjustment device, one or more amplifiers, and a mixer. The down converter includes a signal adjustment stage coupled to receive the mixer output signal, the signal adjustment stage comprising: a temperature compensation device configured to compensate for changes in signal gain due to changes in temperature; a second bandpass filter; a gain adjustment device; one or more amplifiers; and a low pass filter. The down converter comprises an output port coupled to output an adjusted mixer output signal from the signal adjustment stage.

Various technologies described herein pertain to variable gain amplification for a sensor application. A multistage variable gain amplifier system provides variable gain amplification of an input signal. The multistage variable gain amplifier system includes a plurality of amplification stages. The multistage variable gain amplifier system further includes a power detector configured to detect a power level of an input signal received by the multistage variable gain amplifier system. The multistage variable gain amplifier system also includes a controller configured to control the amplification stages based on the power level of the input signal. The multistage variable gain amplifier system can output an output signal such that the amplification stages are controlled to adjust a gain applied to the input signal by the multistage variable gain amplifier system to output the output signal.

Doherty radio frequency (RF) amplifier circuitry includes an input node, an output node, a main amplifier path, and a peaking amplifier path. The main amplifier path is coupled between the input node and the output node and includes a main amplifier. The peaking amplifier path is coupled in parallel with the main amplifier path between the input node and the output node, and includes a peaking amplifier and a peaking variable gain preamplifier between the input node and the peaking amplifier. The peaking variable gain preamplifier is configured to adjust a current provided to the peaking amplifier.

A variable gain amplifier includes a pair of amplification and recentering branches. Each branch includes: a resistive element of variable resistance configured to be driven by a variable gain controller; a digitally-driven variable current source configured to be driven by a compensation current driver unit; a first transistor comprising a gate terminal coupled to an input terminal of the variable gain amplifier, and a source terminal coupled to a first terminal of the resistive element; and a second transistor comprising a gate terminal coupled to a drain terminal of the first transistor, and a source terminal coupled to an output terminal of the variable gain amplifier.

Methods and systems are described for receiving, at an input differential branch pair, a set of input signals, and responsively generating a first differential current, receiving, at an input of an offset voltage branch pair, an offset voltage control signal, and responsively generating a second differential current, supplementing a high-frequency component of the second differential current by injecting a high-pass filtered version of the set of input signals into the input of the offset voltage branch pair using a high-pass filter, and generating an output differential current based on the first and second differential currents using an amplifier stage connected to the input differential branch pair and the offset voltage branch pair.

An apparatus and method to automatically adjust a gain of an analog signal adapted to be transmitted over a twisted pair of telephone lines between a first end (e.g., a DSLAM), and a second end (e.g., a modem), is described. The apparatus comprises an amplifier, and a control mechanism. The amplifier receives the analog signal from a respective first or second end, and transmits the received analog signal in the respective downstream or upstream direction. The control mechanism, which preferably is operative only during a train or re-train mode, senses whether the analog signal is within a specified amplitude range associated with a receiver at the respective second end or first end, and, responsive to a determination that the analog signal is not within the specified amplitude range, determines and generates a control signal. The control signal is operative to adjust a gain of the amplifier to a determined value.

A front end module (FEM) and associated method for receiving signals in a front end module are disclosed. Some embodiments of the FEM have three inputs. The FEM can process the input signals in one of three bypass modes. In bypass modes, switchable tank circuits provide a high impedance to isolate active components from the bypass path. This improves the input return loss in the passive bypass mode and thus improves the performance of the passive bypass mode by allowing the use of LNAs without an input switch. In the active gain mode, one of a plurality of signals are amplified by one of an equal number of amplifiers coupled to the FEM output. Accordingly, the FEM can output signals applied to any one of the FEM inputs in bypass mode, or an amplified version of one of the input signals. In some embodiments, the FEM has only one input and one LNA. In such embodiments, an output selector switch selects between a bypass path and a gain path.