A front-end module may include an acoustic wave filter with a first and second interdigital transducer electrode. The first interdigital transducer electrode may be single-ended with a first input bus bar that receives an input signal and a second input bus bar connected to ground. The second interdigital transducer electrode may be differential with a first output bus bar connected to a first output terminal and a second output bus bar connected to a second output terminal. The front-end module may include a low noise amplifier (LNA) that outputs a differential signal via a differential output and has a differential input connected to the acoustic wave filter. The LNA may include a first input transistor that receives a first signal from the first output terminal of the acoustic wave filter and a second input transistor that receives a second signal from the second output terminal of the acoustic wave filter.

An active balun circuit includes first and second transistors having emitters electrically coupled to each other and configured to output differential signals and a circuit element coupled between the connection point of the emitter of the first transistor and the emitter of the second transistor and a reference potential. The impedance of the circuit element at a particular frequency of the input signal appears significantly larger than impedances at other frequencies. An input signal from an input terminal is inputted to the base of the first transistor. The reference potential is applied to the base of the second transistor. A supply voltage is applied to the collector of the first transistor and the collector of the second transistor. A signal from the collector of the first transistor and a signal from the collector of the second transistor are outputted as the differential signals.

An impedance control unit is disclosed. Also disclosed are a balun unit, an electronic device, and a Doherty amplifier, each comprising the impedance control unit. The impedance control unit comprises a pair of re-entrant type coupled lines, and further comprises an electrical short between the intermediate plane and the ground plane arranged locally inside the pair of coupled lines.

A transmitter device which transmits a first transmit signal and a second transmit signal having different wireless communication standards. The transmitter device includes a power amplifier that amplifies the first transmit signal in a first transmission mode. A first impedance circuit provides the amplified first transmit signal to a radio frequency output port. A second impedance circuit is connected to the first impedance circuit and provides an additional impedance to the first impedance circuit in the first transmission mode. A first switch provides the second transmit signal to the first impedance circuit in a second transmission mode. A second switch connects the second impedance circuit and a ground in the first transmission mode, and floats the second impedance circuit in the second transmission mode.

Wideband baluns with enhanced amplitude and phase balance are provided. The wideband balun includes a first transmission line connected between a first port and a third port, and a second transmission line connected between a second port and a fourth port, and a third transmission line connected between the third port and a reference voltage, such as ground. To enhance phase and/or amplitude balance of the wideband balun, the wideband balun further includes a compensation structure operable to provide at least one of capacitive compensation or inductive compensation to balance the wideband balun. For example, in certain implementations, the compensation structure includes at least one of (i) a capacitor connected between the first port and the second port or (ii) a fourth transmission line connected between the first transmission line and the third port.

A power amplifier, for a transmitter circuit is disclosed, which comprises at least one field-effect transistor having a gate terminal and a bulk terminal. The at least one field-effect transistor is configured to receive an input voltage at the gate terminal and a dynamic bias voltage at the bulk terminal. The power amplifier comprises a bias-voltage generation circuit configured to generate the dynamic bias voltage as a nonlinear function of an envelope of input signal. The input voltage is a linear function of the input signal. The bias-voltage generation circuit comprises a rectifier circuit configured to generate a rectified input voltage and an amplifier circuit, operatively connected to the rectifier circuit, configured to generate the dynamic bias voltage based on the rectified input voltage. The amplifier circuit is a variable-gain amplifier circuit and the power amplifier comprises a control circuit configured to tune the gain of the amplifier circuit.

Coupled line structures for wideband applications are provided herein. In certain embodiments, a coupled line structure includes one transmission line that is segmented in a metal layer and another that is substantially continuous in the metal layer, thereby allowing tighter spacing and higher coupling between the transmission lines relative to what is achievable if both transmission lines were continuous. The high coupling in turn aids in achieving wide bandwidth.

Amplifiers, amplification circuits, and phase shifters, for example, for flexibly adjusting an output phase to thereby meet a requirement of a constant phase on a link in a communications field, are provided. In one aspect, an amplifier includes first, second, and third MOS transistors. The first MOS transistor includes a gate separately coupled to a signal input end and a bias voltage input end, a source coupled to a power supply, and a drain separately coupled to sources of the second and third MOS transistors. A drain of the third MOS transistor is coupled to a ground, and a drain of the second MOS transistor is coupled to a signal output end. The bias voltage input end is configured to receive a bias voltage to adjust a phase difference between an input signal at the signal input end and an output signal at the signal output end.

An apparatus includes a plurality of transmitter channels and a plurality of feedback networks. Each of the plurality of transmitter channels may be coupled to a respective antenna element in a respective group of antenna elements of a phased array antenna. Each of the transmitter channels generally comprises a power amplifier circuit configured to drive the respective antenna element in the respective group of antenna elements to produce and steer a radio-frequency beam. Each of the plurality of feedback networks may be coupled between an output and an input of a respective power amplifier circuit of a respective transmitter channel. Each of the feedback networks generally comprises a resistor and a capacitor connected in series. The respective power amplifier circuit with the feedback network generally maintains a power matching condition with load variation associated with performing beam steering of the radio-frequency beam using the antenna elements of the phased array antenna.

A transmitter device which transmits a first transmit signal and a second transmit signal having different wireless communication standards. The transmitter device includes a power amplifier that amplifies the first transmit signal in a first transmission mode. A first impedance circuit provides the amplified first transmit signal to a radio frequency output port. A second impedance circuit is connected to the first impedance circuit and provides an additional impedance to the first impedance circuit in the first transmission mode. A first switch provides the second transmit signal to the first impedance circuit in a second transmission mode. A second switch connects the second impedance circuit and a ground in the first transmission mode, and floats the second impedance circuit in the second transmission mode.