A radio-frequency module includes a switch performing switching of the connection between a common terminal and a selection terminal, a reception filter having a reception band in a band A as a passband, a transmission filter that has a transmission band in a band B as a passband and has an output terminal connected to the selection terminal, a filter that has the transmission band in a band B as an attenuation band and has an input terminal connected to the selection terminal, a reception path which connects the selection terminal and an input terminal of the reception filter and on which the filter is disposed, a bypass path which connects the selection terminal and the input terminal of the reception filter and on which no filter is disposed, and a transmission path which connects the selection terminal and a transmission terminal and on which the transmission filter is disposed.

A radio-frequency module includes a module substrate. The module substrate includes a first principal surface; a second principal surface on a side of the module substrate that is opposite to the first principal surface; a third principal surface that is recessed toward the first principal surface from the second principal surface in a plan view of the second principal surface; a recessed region in which the third principal surface is a bottom surface; and a protruding region located on an outer periphery of the recessed region, in a plan view of the second principal surface, wherein the protruding region has a via conductor disposed therein, the via conductor extending in a direction perpendicular to the second principal surface and having an end exposed on the second principal surface.

This application provides a narrowband interference isolation method and a communication apparatus. An example method includes: determining a parameter of a narrowband interference signal; determining a coefficient of a first filter based on the parameter of the narrowband interference signal, wherein the first filter is located at a receive end of a master communication device, and the coefficient of the first filter is for filtering out the narrowband interference signal; and sending the parameter of the narrowband interference signal or the coefficient of the first filter to M slave communication devices using an Ethernet operation, administration, and maintenance (OAM) frame, wherein the master communication device is connected to the M slave communication devices, M≥1, and M is an integer.

A PA module includes: a multilayer substrate having a ground pattern layer connected to a ground of a power source; amplifier transistors disposed on the multilayer substrate; a bypass capacitor having one end connected to the collector of the amplifier transistor; a first wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a second wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a third wiring line connecting the other end of the bypass capacitor and the ground pattern layer to each other; and a fourth wiring line formed between the amplifier transistor and the ground pattern layer and between the bypass capacitor and the ground pattern layer and connecting the first wiring line and the third wiring line to each other.

An electronic device may include wireless circuitry with a processor, a transceiver, an antenna, and a front-end module coupled between the transceiver and the antenna. The front-end module may include one or more power amplifiers for amplifying a signal for transmission through the antenna. A power amplifier may include a phase distortion compensation circuit. The phase distortion compensation circuit may include one or more n-type metal-oxide-semiconductor capacitors configured to receive a bias voltage. The bias voltage may be set to provide the proper amount of phase distortion compensation.

A cascade comprising multiple filters according to an embodiment comprises a filter, which includes a splitter configured to split an analog radio-frequency input signal into at least a first signal and a second signal, a first signal path configured to generate, based on the first signal, a time-delayed signal delayed by a predetermined delay time in the time domain, a second signal path configured to generate, based on the second signal, a phase-shifted signal shifted by a controllable predetermined phase shift in the phase domain, and a coupler configured to generate an output signal based on the time-delayed signal and the phase-shifted signal. Using an embodiment may improve a trade-off between frequency-related flexibility and frequency agility of a receiver infrastructure.

A transmission/reception device is configured to convert an optical signal based on a plurality of first optical signals having frequency bands different from each other into an electric signal and output the electric signal as a plurality of first electric signals; receive the plurality of first electric signals, change frequency bands of some or all of a plurality of second electric signals to narrow an interval between frequency bands of two second electric signals having frequency bands adjacent to each other, and output, as third electric signals, electric signals; to receive a plurality of the third electric signals, combine and output the plurality of third electric signals as a fourth electric signal; and receive the fourth electric signal, convert the fourth electric signal into an optical signal, and output the optical signal as a second optical signal.

An RF filter comprising a resonator element and a polymer composition is provided. The polymer composition contains an aromatic polymer and has a melting temperature of about 240° C. or more. The polymer composition exhibits a dielectric constant of about 5 or less and dissipation factor of about 0.05 or less at a frequency of 10 GHz.

An RFID receiver (1) comprises an antenna (11) configured to receive a radio signal (20) from an RFID transmitter (2) and to generate an electrical signal (110) from the radio signal (20) received from the RFID transmitter (2). A decoder circuit (10) is connected to the antenna (11) and configured to extract from the electrical signal (110) generated by the antenna (11) data bits encoded in the electrical signal (110). The decoder circuit (10) comprises an analog-to-digital converter (12) connected directly to the antenna (11) and configured to generate a digital input signal (13) from the electrical signal (110) generated by the antenna (11). A bit extractor (14) is connected to the analog-to-digital converter (12) and configured to extract the data bits from the digital input (13) signal generated by the analog-to-digital converter (12).

Provided is a wireless communication receiver including an antenna for receiving an RF signal; a first mixer, coupled to the antenna, for performing frequency conversion on the RF signal from the antenna by mixing the RF signal with a local oscillator signal to provide a first intermediate frequency (IF) signal; and a first filter, coupled to the first mixer, configured to pass a predetermined band of frequencies of the first IF signal and to generate a first channel signal. The first filter includes a negative feedback loop coupled to the first mixer for performing negative feedback loop control on the first IF signal; and a positive capacitive feedback loop coupled to the first mixer for performing positive capacitive feedback loop control on the first IF signal, the negative feedback loop and the positive capacitive feedback loop being coupled in parallel.