A radio-frequency module includes a module substrate, a power amplifier, and a control circuit configured to control the power amplifier. The control circuit includes a temperature sensor. The power amplifier and the control circuit are stacked one on top of another on a principal surface of the module substrate.

Methods and apparatus are provided. In an example aspect, an amplifier protection circuit is provided. The amplifier protection circuit comprises an input for receiving a signal from a first amplifier, and an isolation circuit between the input and an output of the amplifier protection circuit. The isolation circuit is configured to sense a backward signal propagating from the output of the amplifier protection circuit towards the input to provide a sensed signal, and to provide at least one cancellation signal based on the sensed signal to at least partially cancel the backward signal.

Provided is a radio-frequency L-DRX device having a receiving port (RXOUT) and a polling transmitting port (SRS) used for connection to a radio-frequency transceiver, and an antenna port (ANT) for connection to an antenna. The radio-frequency L-DRX device includes: a first switching unit connected to the antenna port (ANT) and the polling transmitting port (SRS) and configured to selectively switch on a receiving path where the receiving port (RXOUT) is located and a transmitting path where the polling transmitting port (SRS) is located; a first filtering unit disposed in the receiving path or the transmitting path and configured to perform filtering processing on a received or transmitted radio-frequency signal; and a first low noise amplifier disposed in the receiving path and having an output terminal connected to the receiving port (SRS), and configured to amplify the filtered radio-frequency signal to be outputted via the receiving port (SRS).

A decrease in isolation is suppressed when transmitting both a first transmission signal and a second transmission signal in simultaneous communication. A radio frequency module includes a first transformer and a second transformer. The first transformer is included in a first differential power amplifier to amplify the first transmission signal. The second transformer is included in a second differential power amplifier to amplify the second transmission signal to be simultaneously communicated with the first transmission signal. A direction of magnetic flux generated in the first transformer is different from a direction of magnetic flux generated in the second transformer.

An amplifier of a transmitter includes an input that receives an input signal and generates an amplified signal at an output. A digital power meter is coupled to the input of the amplifier, generates an estimated amplified signal, and determines peak and average powers of the estimated amplified signal. An output power detector coupled to the output of the amplifier determines peak and average powers of the amplified signal. A controller coupled to the digital power meter and the output power detector determines an estimated crest factor based on the peak and average powers of the estimated amplified signal, an amplified crest factor based on the peak and average powers of the amplified signal, and an error vector magnitude based on the estimated and amplified crest factors. The controller, which is also coupled to the amplifier, then adjusts operation of the amplifier based on the error vector magnitude.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a capability message indicating a capability of the UE to perform bandwidth-limited envelope tracking or a capability of the UE to compensate for bandwidth-limited envelope tracking distortion. The UE may receive a request for the UE to activate bandwidth-limited envelope tracking or a request for the UE to compensate for bandwidth-limited envelope tracking distortion. In some examples, the UE may transmit an uplink message using a bandwidth-limited envelope tracking configuration. In other examples, the UE may receive a downlink message and use digital post distortion (DPoD) to correct bandwidth-limited envelope tracking distortions in the downlink message. Aspects of the present disclosure may enable the UE to use bandwidth-limited envelope tracking and DPoD for wideband signal transmissions, which may result in lower power consumption at the UE.

A wireless signal processing circuit includes plural phase switchers, plural variable amplifiers and plural mixers. The plural phase switchers are provided on each of plural paths along which all in-phase signal and a quadrature signal are distributed. The plural phase switchers rotate the phases of the signals by signal phase rotation amounts according to a transmission direction of a transmission signal. The plural variable amplifiers alter amplitudes of input signals or output signals of the corresponding phase switchers in accordance with the transmission direction of the transmission signal. The plural mixers up-convert frequencies of the signals processed by the corresponding phase switchers and variable amplifiers.

An antenna module includes a dielectric substrate and a radiation element disposed on the dielectric substrate. The dielectric substrate includes a flat portion (131) and a flat portion (130) having mutually different normal directions, and a bent portion connecting the flat portion (131) and the flat portion (130) to each other. The flat portion (131) has a protruding portion partially protruding in a direction toward the flat portion (130) along the flat portion (131) from a boundary portion between the bent portion and the flat portion (131). The flat portion (131) and the bent portion are connected to each other at a position where the protruding portion is not provided in the flat portion (131). At least a part of the radiation element is disposed on the protruding portion.

The present invention discloses a millimeter-wave isolation device, comprising a first isolated circuit and a second isolated circuit and further comprising a millimeter-wave transceiver. An output end of the first isolated circuit is connected to an input end of the millimeter-wave transceiver. An output end of the millimeter-wave transceiver is connected to an input end of the second isolated circuit. The first isolated circuit and the second isolated circuit are isolated by virtue of the millimeter-wave transceiver. By adopting a short distance transmission mode with millimeter-waves taken as carrier waves, a bandwidth can reach 200 kHz to 20 GHz, and a transmission speed can reach 100 kbps to 10 Gbps. The speed is high, whereby the millimeter-wave isolation device can be applicable to any scenario. A millimeter-wave carrier wave antenna is small, and through the antenna, either wireless transmission or signal isolation can be achieved.

An elastic wave device includes an LiNbO.sub.3 substrate, a first elastic wave resonator including a first IDT electrode and a first dielectric film, and a second elastic wave resonator including a second IDT electrode and a second dielectric film. A Rayleigh wave travels along at least one surface of the elastic wave device. A thickness of the first dielectric film differs from a thickness of the second dielectric film. A propagation direction of an elastic wave in the first elastic wave resonator coincides with a propagation direction of an elastic wave in the second elastic wave resonator. Euler angles of the LiNbO.sub.3 substrate fall within a range of (0°±5°, θ, 0°±10°).