Improved dither detection, measurement, and voltage bias adjustments for an electro-optical modulator are described. The electro-optical modulator generally includes RF electrodes and phase heaters interfaced with semi-conductor waveguides on the arms of Mach-Zehnder interferometers, where a processor is connected to output a bias tuning voltage to the electro-optical modulator for controlling optical modulation. A variable gain amplifier (VGA) can be configured with AC coupling connected to receive a signal from a transimpediance amplifier (TIA) that is configured to amply a photodetector signal from an optical tap that is used to measure an optical signal with a dither signal. The analog to digital converter (ADC) can be connected to receive output from the VGA. The processor can be connected to receive the signal from the ADC and to output the bias tuning voltage based on evaluation of the signal from the tap.

An amplifier with temperature compensation where the amplifier has transistors configured to amplify a received signal to create an amplified signal. The amplifier gain changes over temperature. A gain control circuit, connected to the amplifier, that adjusts the amplifier gain responsive to a gain control signal. A temperature compensation circuit includes numerous elements. A constant current source that generates a constant current which is used to create a constant voltage. A temperature dependent current source that generates a temperature dependent current which is used to create a temperature dependent voltage, such that the temperature dependent current source has an inverse temperature dependance as compared to the amplifier. An operational amplifier compares the constant voltage to the temperature dependent voltage and generates an offset signal which varies over temperature. A gated buffer is configured to receive the offset signal and responsive thereto, selectively modify the gain control signal.

An electronically scanned antenna comprising a travelling wave guiding structure having a bottom conductor and a top conductor developing each along a first direction, the top conductor comprising a plurality of first conductive patches arranged periodically along said first direction and connected in series by tuning circuits; the electronically scanned antenna further comprising a plurality of amplifiers arranged for compensating resistive and radiation losses along the length of the travelling wave guiding structure.

An electronic device may include wireless circuitry with a baseband processor, a transceiver circuit, a front-end module, and an antenna. The front-end module may include amplifier circuitry such as a low noise amplifier for amplifying received radio-frequency signals. The low noise amplifier is operable in a non-carrier-aggregation (NCA) mode and a carrier aggregation (CA) mode. The low noise amplifier may include a first input stage, a second input stage, a complementary degeneration transformer, and an input impedance compensation circuit. During the NCA mode, the first input stage is turned on while the second input stage is turned off, the degeneration transformer is controlled to provide maximum inductance, and the compensation circuit is turned on to provide input matching. During the CA mode, the first and second input stages are turned on, the degeneration transformer is adjusted to provide less inductance, and the compensation circuit is turned off.

An example method of operation may include identifying, in a particular room environment, a number of speakers and one or more microphones on a network controlled by a controller and amplifier, providing test signals to play sequentially from each amplifier channel of the amplifier and the speakers, monitoring the test signals from the one or more microphones simultaneously to detect operational speakers and amplifier channels, providing additional test signals to the speakers to determine tuning parameters, detecting the additional test signals at the one or more microphones controlled by the controller, and automatically establishing a background noise level and noise spectrum of the room environment based on the detected additional test signals.

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 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.

An audio preamplifier (1) for a microphone, including: a chassis (2) with at least one audio input (17) and at least one audio output, a control panel (3) including a gain selector (10) being arranged on one of the sides of the chassis (2), the chassis (2) further including a receiving compartment inside which a first connector is arranged; and a cartridge (6) comprising a preamplification circuit and a gain control circuit, the cartridge (6) further having a second connector complementary to the first connector, the cartridge (6) being configured for being inserted in a removable manner into the receiving compartment of the chassis (2) so as to connect the first and second connectors. An audio preamplification kit includes an audio preamplifier (1) and a plurality of additional cartridges.

An analog front-end device includes an amplifier circuit, a first gain control circuit, and a tracking circuit. The amplifier circuit is configured to generate a first output signal according to a first input signal. The first gain control circuit is configured to set a first electronic component according to a first gain control signal and transmit the first input signal to a first input terminal of the amplifier circuit via the first electronic component, in which a terminal of the first electronic component is selectively coupled to the first input terminal or a first predetermined node. The tracking circuit is configured to adjust a level of the first predetermined node according to a level of the first input terminal, in order to reduce a voltage difference between the first input terminal and the first predetermined node.