A method and system for phase correction in a receiver receives a plurality of samples and filters the samples using a polyphase FIR filter. The samples are simultaneously shifted, centered and channelized using a MUX/negate process and a fast Fourier transform (FFT).

An acoustic wave resonator includes: a piezoelectric substrate; and an interdigital transducer (IDT) located on the piezoelectric substrate, the IDT including a pair of comb-shaped electrodes having a plurality of electrode fingers and a bus bar to which the plurality of electrode fingers are coupled, the IDT having: a first region in which a pitch of electrode fingers is substantially constant; a second region in which a pitch of electrode fingers decreases at closer distances to an outer side; and a third region in which a pitch of electrode fingers increases at closer distances to an outer side, the second region being located outside the first region in an arrangement direction of the plurality of electrode fingers, and the third region being located outside the second region in the arrangement direction.

A transmitting and receiving circuit that transmits and receives signals using coaxial cables includes an input/output terminal that delivers and receives signals, a first port, a second port, a switch, and a ceramic-based electro-static discharge protector. The first port transfers a transmitted signal in a first transmission frequency band width and a received signal in a first reception frequency band width. The second port transfers a transmitted signal in a second transmission frequency band width and a received signal in a second reception frequency band width. The switch connects a common port to one of the first port and the second port. The common port is connected to the input/output terminal on one end of the common port and to the switch on the other end. The electro-static discharge protector is connected between the common port and the ground potential.

A multiplexer includes a common terminal connected to an inductance element at a connection path with an antenna element, filter elements including different pass bands and connected to the antenna element with the common terminal therebetween, and an inductance element arranged in series between a transmission filter with a largest capacitance when viewed from the antenna side among the filter elements and the common terminal. An inductive component of the inductance element and a capacitive component of the transmission filter element define an LC series resonant circuit, and a resonant frequency of the LC series resonant circuit is lower than any of pass bands of the filter elements.

A filter includes two series arm resonators electrically connected in series between two input/output terminals, a parallel arm resonator electrically connected between a ground and a series arm between the two series arm resonators, an inductor electrically connected in parallel to the two series arm resonators, and a matching circuit electrically connected between one of the two series arm resonators and one of the input/output terminals, wherein the two series arm resonators and the parallel arm resonator define a pass band of a bandpass filter, the two series arm resonators and the inductor define an LC resonant circuit, respective anti-resonant frequencies of each of the two series arm resonators and a resonant frequency of the parallel arm resonator are located in a pass band of the LC resonant circuit, and a resonant frequency of the LC resonant circuit is lower than the resonant frequency of the parallel arm resonator.

A multiplexer includes a common terminal connected to an inductance element at a connection path with an antenna element, filter elements including different pass bands and connected to the antenna element with the common terminal therebetween, and an inductance element arranged in series between a transmission filter with a largest capacitance when viewed from the antenna side among the filter elements and the common terminal. An inductive component of the inductance element and a capacitive component of the transmission filter element define an LC series resonant circuit, and a resonant frequency of the LC series resonant circuit is lower than any of pass bands of the filter elements.

Methods and systems are provided for use of tunable bandwidths. An example system may comprises a plurality of filters, with each of filters being configured for filtering signals corresponding to a particular frequency band associated with a particular stream. One or more adjustments may be determined and applied to one or more of the plurality of filters. The adjustments may comprise modifications to at least one frequency band associated with at least one of the plurality of filters. Leakage affecting the plurality of filters may be measured or estimated, and a compensation adjustment applicable to particular transmitted and/or received signals may be determined based on measured or estimated leakage. The leakage may be estimated based on analysis of digital baseband signals corresponding to transmitted and/or received signals.

A transceiver system may be configured to provide tunable bandwidths. The transceiver may comprise a signal processing component and a filtering component, which may comprise a plurality of filters. The signal processing component may determine one or more adjustments that are applicable to one or both of a first filter that is configured for filtering signals corresponding to a first frequency band associated with a first stream, and a second filter that is configured for filtering signals corresponding to a second frequency band associated with a second stream. The one or more adjustments may correspond to modifications in one or both of the first frequency band and the second frequency band. The one or more adjustments may be communicated to the filtering component, which may apply the adjustments to one or more of the plurality of filters.