A multiple-path amplifier (e.g., a Doherty amplifier) includes first and second amplifier input terminals and an amplifier output terminal integrally-formed with a semiconductor die, and at least two amplifier cells positioned adjacent to each other between the amplifier input terminals and the amplifier output terminal. Each amplifier cell includes first and second transistors (e.g., field effect transistors) integrally-formed with the semiconductor die, where the first and second transistors each include a transistor input (e.g., a gate terminal) and a transistor output (e.g., a drain terminal). The first transistor input is coupled to the first amplifier input terminal, and the second transistor input is coupled to the second amplifier input terminal. A combining node is coupled to the second transistor output and to the amplifier output terminal, and a first phase shift element (e.g., an inductor) is electrically connected between the first transistor output and the combining node.

A power amplifier circuit includes lower-stage and upper-stage differential amplifying pairs, a combiner, first and second inductors, and first and second capacitors. First and second signals are input into the lower-stage differential amplifying pair. The upper-stage differential amplifying pair outputs first and second amplified signals. The combiner combines the first and second amplified signals. The lower-stage differential amplifying pair includes first and second transistors. A supply voltage is supplied to the collectors of the first and second transistors. The first and second signals are supplied to the bases of the first and second transistors. The upper-stage differential amplifying pair includes third and fourth transistors. A supply voltage is supplied to the collectors of the third and fourth transistors. The emitters of the third and fourth transistors are grounded via the first and second inductors and are connected to the first and second transistors via the first and second capacitors.

An apparatus has a Radio Frequency (RF) signal generator to produce RF signals phase shifted relative to one another in accordance with RF frequency waveform parameters. Amplifier chains process the RF signals to produce channels of amplified RF signals. Each amplifier chain has amplifiers and at least one amplifier has a tunable gate voltage synchronized with the RF signals.

The present disclosure provides an amplifier circuit that includes one or more amplifier stages, each of the one or more amplifier stages including a complementary transistor configuration. The complementary transistor configuration includes an NMOS transistor and a PMOS transistor. The NMOS transistor is electrically coupled in parallel to the PMOS transistor. The amplifier circuit further includes an output amplifier stage electrically coupled to an output of the one or more amplifier stages, the output amplifier stage including a non-complementary transistor configuration including one or more NMOS transistors or PMOS transistors.

In an embodiment, a class-AB amplifier includes: an output stage that includes a pair of half-bridges configured to be coupled to a load; and a current sensing circuit coupled to a first half-bridge of the pair of half-bridges. The current sensing circuit includes a resistive element and is configured to sense a load current flowing through the load by: mirroring a current flowing through a first transistor of the first half-bridge to generate a mirrored current, flowing the mirrored current through the resistive element, and sensing the load current based on a voltage of the resistive element.

Various embodiments disclose a method and a device including: an antenna, a switching regulator, communication chip including an amplifier and a linear regulator operably connected to the amplifier and the switching regulator, the communication chip configured to transmit a radio-frequency signal from the electronic device through the antenna, and control circuitry configured to control the communication chip such that the linear regulator provides the amplifier with a voltage corresponding to an envelope of an input signal input to the amplifier, the input signal corresponding to the radio-frequency signal.

In certain aspects, a receiver includes first amplifiers, wherein each one of the first amplifiers comprises an input and an output. The receiver also includes second amplifiers, wherein each one of the second amplifiers comprises an input and an output, and the outputs of the second amplifiers are coupled to a combining node. The receiver also includes transmission lines, wherein each one of the transmission lines is coupled between the output of a respective one of the first amplifiers and the input of a respective one of the second amplifiers. The receiver further includes a load coupled to the combining node, and receiver elements, wherein each one of the receiver elements comprises an input and an output, and the output of each one of the receiver elements is coupled to the input of a respective one of the first amplifiers.

Examples disclosed herein relate to a high gain active relay antenna system. The active relay antenna system comprises a first antenna pair having a first receive antenna and a first transmit antenna to communicate wireless signals in a forward link from a base station to a plurality of users; and a second antenna pair having a second receive antenna and a second transmit antenna to communicate wireless signals in a return link from the plurality of users to the base station. The active relay antenna system further comprises a first active relay section and a second active relay section to provide for adjustable power gain in the wireless signals.

A power converter produces power at a greater voltage than provided by a power source, while drawing power from the power source, wherein the power converter has a variable input current limit or a variable input power limit. One or more audio amplifiers are configured into i) drawing power from the power source bypassing the power converter and ii) drawing power from the power converter, according to audio signal amplitude, during audio playback and in accordance with an audio signal being amplified. A load of each amplifier is determined for when the amplifier is drawing power from the power source bypassing the power converter. The variable input limit of the power converter is adjusted in accordance with the determined load, during the audio playback. Other aspects are also described and claimed.

An amplifier includes a first circuitry, a second circuitry, and a plurality of amplifier circuitries. The first circuitry controls an enable signal. The second circuitry controls a bias signal. Circuitries which output signals are decided from among the plurality of circuitries based on the enable signal, and each of the circuitries which output the signals amplifies an input signal with a gain corresponding to the bias signal.