A radio frequency (RF) front-end (RFFE) may include a differential hard-switching RF power amplifier. The RFFE may also include a ground bounce circuit coupled to the differential hard-switching RF power amplifier.

Apparatus and methods for performing wireless communications are provided. In some embodiments, an apparatus includes a transformer including a first winding, a second winding, and a third winding. The apparatus also includes a first transmitter circuit coupled with the first winding, and a second circuit coupled with the second winding. The third winding is coupled with an antenna. The first transmitter circuit is configured to transmit a first signal to the antenna via magnetic coupling between the first winding and the third winding. The second circuit is configured to tolerate without damage a second signal from the first transmitter circuit, wherein the second signal is generated from the first signal via magnetic coupling between the first winding and the second winding. A turn ratio between the first winding and the second winding can be configured to limit a voltage of the second signal to be within a pre-determined threshold.

A digital power amplification circuit includes a decoding block configured to receive a first stream of digital codes and to derive from the first stream a second stream of digital codes, the decoding block including a decoder configured to decode the digital codes of the first stream and the second stream at a first clock rate, a main digital power amplifier configured to receive the decoded digital codes of the first stream, an upsampler configured to upsample the decoded digital codes of the second stream to a second clock rate that is greater than the first clock rate, an auxiliary digital power amplifier configured to receive the decoded digital codes of the second stream upsampled to the second clock rate, and a summer configured to sum (i) a main output signal of the main digital power amplifier and (ii) an auxiliary output signal of the auxiliary digital power amplifier.

A switched-capacitor power amplifier comprising a plurality of cells and methods for its operation are described. Switched signal lines switch supply to respective capacitors. Switches connect respective signal lines to a first supply and switches connect respective signal lines to a second supply. Pairs of switches on each signal line are switched so that one is switched off whilst the other is switched on. In a full amplitude mode, operation of the switches provides an output having a peak determined by the first supply. A switch signal line is provided between nodes in respective signal lines, a switch being provided in the switch signal line. In a half amplitude mode, switch is switched at the radio frequency in the other direction to that of switches connecting the signal lines to respective ones of the first and second supplies with the other switches being kept open.

Systems and methods are provided for dynamically biasing power amplifiers. A power amplifier (PA) that amplifies an input signal may be controlled based on processing of the input signal. The controlling may include adjusting biasing applied to the power amplifier (PA). The processing of the input signal may include applying clipping to the input signal and determining one or more parameters of the input signal. The biasing applied to the power amplifier (PA) may be adjusted based on the one or more parameters of the input signal. The clipping may be configured such that signals applied to positive and negative sides of the power amplifier (PA) are not differential.

A wireless electric field power transmission system comprises: a transmitter comprising a transmitter antenna, the transmitter antenna comprising at least two conductors defining a volume therebetween; and at least one receiver, wherein the transmitter antenna transfers power wirelessly via electric field coupling when the at least one receiver is within the volume.

The present invention discloses a matching circuit with switchable load lines, a load line switching method and a power amplifier. The matching circuit matches the output impedance of the power amplifier, which amplifies an input signal and outputs an amplified signal. The matching circuit comprises a filter circuit and a switch group for load line selection, the output end of the filter circuit is connected to the switch group. The switch group comprises at least two independent switches, each switch independently constitutes a signal line, and each switch is configured with an external control signal to control on/off. The matching circuit provided by the invention adopts a switch group composed of at least two independent switches, and each independent switch forms a signal line to connect loads, so that multiple loads can be connected at the same time.

Disclosed is an RF module. The substrate includes a first layout area and a second layout area. The first RF chip is located in the first layout area, including a first power amplifier and a second power amplifier. The first switch chip is arranged in the first layout area and connected to the output ends of the first and second power amplifier. The second RF chip is arranged in second layout area, including a third power amplifier. The second switch chip is arranged in the second layout area and connected to the output end of the third power amplifier. The RF module shortens the transmission distance of RF signals between the first RF chip and first switch chip and between the second RF chip and second switch chip by arranging components in two areas separately, thus reducing the insertion loss and interference and improving the output quality of RF signals.

Certain aspects of the present disclosure generally relate to techniques and apparatus for operating a wireless receiver of the apparatus in a high linearity mode. An example method includes operating the apparatus in a first mode with transmission of a plurality of transmit signals. The method also includes attenuating a received signal via an attenuator while operating the apparatus in the first mode. The method further includes amplifying the attenuated signal with an amplifier while operating the apparatus in the first mode. For certain aspects, the method further involves operating the apparatus in a second mode, bypassing the attenuator while operating the apparatus in the second mode, and amplifying the received signal with the amplifier while operating the apparatus in the second mode.

A balanced amplifier can utilize a common mode choke to suppress even harmonics in the signals of the balanced amplifier. The common choke can be coupled between cascaded balanced amplifier pairs to receive the differential output signals from one of the balanced amplifier pairs and to provide conditioned signals to the other of the balanced amplifier pairs. The common mode choke can improve the amplitude and phase balance between the differential output signals by providing increased impedance to the passage of common mode signals such as even harmonics.