A radio-frequency circuit includes a switch and three filters. The switch is connected to an antenna connecting terminal. One filter has a pass band corresponding to a first sub-band and is configured to connect to the antenna connecting terminal via the switch. The first sub-band is included in a first band used for TDD communication. Another filter has a pass band corresponding to a second sub-band included in the first band and is configured to connect to the antenna connecting terminal via the switch. There is a gap between the first sub-band and the second sub-band. The remaining filter has a pass band corresponding to a third sub-band and is configured to connect to the antenna connecting terminal via the switch. The third sub-band includes the first sub-band, the second sub-band, and the gap.

A radio-frequency circuit includes a filter and a band elimination filter. The filter has a pass band corresponding to a first sub-band. At least part of the first sub-band is included in a first band used for TDD communication. The band elimination filter is connected to the filter and has a first elimination band which corresponds to a second sub-band included in the first band. The second sub-band is located between a third sub-band and a fourth sub-band. The third and fourth sub-bands are included in the first band. The first sub-band includes the second, third, and fourth sub-bands.

A high-frequency circuit includes a power amplifier for a communication band A, and a power amplifier for a communication band B. Transmission in the communication band A, transmission in the communication band B, and reception in the communication band C can be simultaneously used. A frequency range of intermodulation distortion generated between a second harmonic wave of a transmission signal of the communication band A and a fundamental wave of a transmission signal of the communication band B, overlaps with at least part of a reception band of the communication band C. The power amplifier includes amplifying elements and an output trans including coils. One end of the coil is connected with an output of the amplifying element, the other end of the coil is connected with an output of the amplifying element, and one end of the coil is connected with an output terminal of the power amplifier.

A self-controlled radio frequency (RF) filtering unit that may include (i) a frequency bank that comprises first till fourth band pass filters (BPFs) having first till fourth frequency bands respectively; wherein at least one harmonic of at least one fundamental frequency within the first frequency band pass an interference risk for at least one other frequency band; (ii) a measurement circuit configured to measure the input power received in two or more frequency bands and to provide a power measurement result; (ii) an input RF switch comprising a first RF switch input port, a first RF switch output port, and a second RF switch output port; wherein input RF switch is configured to select a selected RF switch output port, based at least in part on the power measurement result, out of the first and second RF switch output ports; wherein the first RF switch output port is RF coupled to an input of the second BPF; wherein the second RF switch output port is RF coupled to inputs of the first BPF, the third BPF and the fourth BPF; and (ii) an output RF switch comprising a second RF switch input port, a third RF switch input port, and a third RF switch output port; wherein output RF switch is configured to select, based at least in part on the power measurement result, a selected RF switch input port out of the second and third RF switch input ports; wherein the second RF switch input port is RF coupled to outputs of the first BPF and the second BPF; and wherein the third RF switch input port is RF coupled to outputs of the third BPF and the fourth BPF.

Front end architectures are described that tailor duplexer characteristics to enable the removal of many of the impedance matching components typically included in a receive signal path between an antenna and receive amplifiers and in a transmit signal path between transmit amplifiers and the antenna. By tailoring duplexer characteristics, targeted impedance matching can be achieved for front end architectures. This enables the front-end architecture to impedance match without including typical impedance matching components along a signal path between the antenna and an amplifier. This can be implemented on the transmit signal path (e.g., between a power amplifier (PA) and the antenna), on the receive signal path (e.g., between the antenna and a low noise amplifier (LNA)), or both the transmit signal path and the receive signal path. Thus, the disclosed front end architectures are configured to reduce or eliminate the number of components required for impedance matching.

An apparatus comprises a digital processing device configured to generate a digital transmission signal, a digital-to-analog converter connected to the digital processing device and configured to convert the digital transmission signal into an analog transmission signal, and a power amplifier connected to the digital-to-analog converter and configured to amplify the analog transmission signal. An antenna filter is connected to the power amplifier and configured to filter the amplified analog transmission signal; the antenna filter is configured to pass frequencies in at least one passband and to attenuate frequencies in at least one stopband. The digital processing device is configured to perform a process of reducing peak power in the digital transmission signal; in this process error components having different frequencies are produced. A frequency spectrum of the error components is manipulated such that a part of the error components is deposited in the stopband of the antenna filter.

Apparatus and methods for radio frequency front-ends are provided. In certain configurations, a radio frequency front-end includes ultrahigh band (UHB) transmit and receive modules employed for both transmission and reception of UHB signals via at least two primary antennas and at least two diversity antennas, thereby supporting both 4×4 receive MIMO and 4×4 transmit MIMO with respect to one or more UHB frequency bands, such as Band 42, Band 43, and/or Band 48. The radio frequency front-end can operate with carrier aggregation using one or more UHB carrier frequencies to provide flexibility in widening bandwidth for uplink and/or downlink communications.

In an acoustic wave device, a piezoelectric body is directly or indirectly provided on a high acoustic velocity material layer, an interdigital transducer electrode is directly or indirectly provided on the piezoelectric body, the interdigital transducer electrode includes a first busbar, a second busbar spaced away from the first busbar, a plurality of first electrode fingers, and a plurality of second electrode fingers, and a weighting is applied to the interdigital transducer electrode by providing a floating electrode finger not electrically connected to the first busbar or the second busbar or applied by providing an electrode finger formed by metallizing a gap between the first electrode fingers or a gap between the second electrode fingers to integrate the first electrode fingers or the second electrode fingers.

A radio communication apparatus includes: a first radio frequency subunit, configured to modulate a third analog baseband signal into a third carrier signal, and send the third carrier signal to a first switch; a second radio frequency subunit, configured to modulate a fourth analog baseband signal into a fourth carrier signal, and send the fourth carrier signal to a second switch; the first switch; the second switch; and the first duplexer shared by a first switch and a second switch, configured to receive the third carrier signal from the first switch, receive the fourth carrier signal from the second switch, filter the third carrier signal and the fourth carrier signal to combine the third carrier signal and the fourth carrier signal to obtain a second carrier aggregation signal, and input the second carrier aggregation signal to a first antenna.

A transmission interface between at least a master module and a slave module is proposed. The transmission interface includes a predetermined number of physical transmission medium(s). Each physical transmission medium is arranged to carry a multiplexed signal in which at least two signals are integrated, and the predetermined number is not smaller than a number of intermediate frequency (IF) stream(s) to be transmitted.