A quasi-differential amplifier with an input port and an output port. The amplifier has a phase shifter network with a first port connected to the input port, a second port, and a third port. A first amplifier has an input connected to the second port of the phase shifter network, and an output, and a second amplifier has an input connected to the third port of the phase shifter network, and an output. A balun circuit includes a first differential port connected to an output of the first amplifier, a second differential port connected to an output of the second amplifier, and a single-ended port. An output matching network is connected to the single-ended port of the balun circuit and to the output port.

Systems and methods are provided herein that include an amplifier arrangement and a balun arrangement that accommodate two or more frequency bands using various common components that are operated and/or coupled in differing ways based upon which frequency band is in operation.

A calibration apparatus is used for calibrating characteristics of a power amplifier (PA) in a transmitter. The calibration apparatus includes an adaptive bias generator circuit that is used to track an envelope of an input signal received by control terminals of transistors of the PA and generate an adaptive bias voltage to the control terminals of the input transistors in response to the envelope of the input signal.

A microphone device, an interface circuit and method are provided for managing a potential difference in sensitivity to a detected environmental stimulus associated with a sensor arrangement, where multiple electrical signals forming a differential signal can be produced, and the multiple electrical signals can be better balanced. Such an interface circuit, which can be used within a microphone device includes a bias voltage generator having one or more bias output voltage terminals, where a respective one of one or more DC bias voltages is produced at each of the bias output voltage terminals, for being coupled to a pair of transduction elements of a sensor. The interface circuit further includes an amplifier circuit having a first input terminal coupled to a first one of the pair of output terminals of the sensor and having a second input terminal coupled to a second one of the pair of output terminals of the sensor, the amplifier circuit producing a differential output signal. The interface circuit still further includes a compensation circuit coupled to the amplifier circuit for producing a balance signal based on an output signal being produced by the amplifier circuit, wherein the balance signal compensates for any difference in amplitude in the first and second electrical signals that are received by the amplifier circuit from the sensor.

The present invention relates to a push-pull amplifying unit and a Doherty amplifier. The push-pull amplifying unit comprises a first amplifier, a second amplifier, a first shunt inductor, and a second shunt inductor. The first and second shunt inductors have mutually connected second terminals and are inductively coupled to increase the impedance between the first output and the virtual ground and the impedance between the second output and the virtual ground at a fundamental frequency of a signal to be amplified by the push-pull amplifying unit relative to those impedances in the absence of said inductive coupling, and to decrease the impedance between the first output and the virtual ground and the impedance between the second output and the virtual ground at a second harmonic frequency of the signal to be amplified relative to those impedances in the absence of said inductive coupling.

Aspects described herein include devices and methods for smart ultra wideband transmissions. In one aspect, an apparatus includes pulse generation circuitry configured to output a plurality of transmission (TX) pulse samples at a selected signal sample rate, where each pulse sample of the plurality of TX pulse samples comprises a value associated with a pulse amplitude at a corresponding sample time The apparatus includes a plurality of power amplifier (PA) cells, with each PA cell of the plurality of PA cells comprising a corresponding current source and associated gates, and where the associated gates of a PA cell are selectable to configure an on state and an off state. Logic circuitry of the apparatus is configured to set the on state or the off state for each PA cell.

Combiners for Doherty power amplifier systems are provided herein. In certain embodiments, a combiner structure includes a first balun combiner for combining an output of a first auxiliary amplifier and a second auxiliary amplifier, and a second balun combiner for combining the output of a main amplifier and an output of the first balun combiner. Each combiner can include a balun having a first conductor connected between a first input port and an output port, a second conductor connected between an isolated node and a second input port and magnetically coupled to the first conductor. An isolation capacitor is connected between the first input port and the isolated node, and an output capacitor is connected between the second input port and the output port. In certain implementations, the balun combiner further includes a termination capacitor between the isolated node and ground.

Wireless circuitry can have an antenna connected to a transmitting amplifier and a receiving amplifier. The wireless circuitry may be operable in a transmit mode during which only the transmitting amplifier is active and in a receive mode during which only the receiving amplifier is active. The transmitting amplifier may be connected to the antenna via a balun and a radio-frequency coupler without an intervening switch that is enabled during the transmit mode and disabled during the receive mode. The transmitting amplifier may include input transistors, cascode transistors, first switches configured to selectively decouple gate terminals of the cascode transistors from a bias voltage, output capacitors, and second switches configured to selectively decouple the output capacitors from a ground line. The first and second switches are turned on during the transmit mode and are turned off during the receive mode to increase an output impedance of the transmitting amplifier.

Wireless circuitry can have an antenna connected to a transmitting amplifier and a receiving amplifier. The wireless circuitry may be operable in a transmit mode during which only the transmitting amplifier is active and in a receive mode during which only the receiving amplifier is active. The transmitting amplifier may be connected to the antenna via a balun and a radio-frequency coupler without an intervening switch that is enabled during the transmit mode and disabled during the receive mode. The transmitting amplifier may include input transistors, cascode transistors, first switches configured to selectively decouple gate terminals of the cascode transistors from a bias voltage, output capacitors, and second switches configured to selectively decouple the output capacitors from a ground line. The first and second switches are turned on during the transmit mode and are turned off during the receive mode to increase an output impedance of the transmitting amplifier.

Disclosed is an output matching network including a first transmission line and a second transmission line each having one end connected to a respective balanced port of a pair of balanced ports; a third transmission line having one end connected to an unbalanced port; and a fourth transmission line. A first capacitor is connected to the unbalanced port and a load. A second capacitor is connected to an end of the fourth transmission line. The third and fourth transmission lines are coupled to the first and second transmission lines.