Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

An acoustic filter device for telecommunication devices includes a first acoustic band pass filter having a corresponding first passband and a second acoustic band pass filter having a corresponding second passband. The second acoustic band pass filter is connected in parallel with the first acoustic band pass filter to provide a combined passband including the first and second passbands.

In one aspect, a time division interleaving band-pass filter can be used in voice activity detection, which operates at different central frequencies in respective intervals of a predetermined period of time. The band-pass filter circuitry includes multiple band-pass filtering channels sharing a common transistor circuit, bias circuit and current mirror circuit. The multiple band-pass filtering channels operate in a time division interleaving manner, which enables the sharing of the common set of band-pass filter circuitry components. Thus, the present invention allows a reduced chip area as the area does not increase proportionally with the number of filtering channels. The invention also mitigates the influence of transistor fabrication variations on the filter's central frequencies. Moreover, pulse durations t.sub.i are additionally introduced to the determination of the central frequencies, dispensing with the need for matching of current mirror circuits and transistors and resulting in higher accuracy of the band-pass filter's central frequencies.

A method and an apparatus for signal processing: implementing step-by-step orthogonal decomposition of an original signal to be inputted; on the basis of the number of layers of orthogonal decomposition and the edge high frequency bandwidth of the original signal after orthogonal decomposition, generating a finite-length unit impulse response FIR filter; using the FIR filter to filter the edge high-frequency signal of the original signal; and, after passing the signal obtained after filtering and the low frequency signal obtained at each stage of orthogonal decomposition through an orthogonal filter bank, implementing signal synthesis processing.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A novel and useful high-order discrete-time charge rotating (CR) infinite impulse response (IIR) low pass filter is presented. The filter utilizes history capacitor arrays incorporating banks of capacitors. A linear interpolation technique is used in the IIR filter with second order antialiasing filtering, whose transfer function is sinc(x).sup.2 per stage. It also uses a g.sub.m cell, rather than operational amplifiers, and is thus compatible with digital nanoscale technology. A 7.sup.th-order charge-sampling discrete time filter is disclosed. The order of the filter is easily extendable to higher orders. The charge rotating filter is process scalable with Moore's law and amenable to digital nanoscale CMOS technology. Bandwidth of the filter is precise and robust to PVT variation. The filter exhibits very low power consumption per filter pole, low input-referred noise, wide tuning range, excellent linearity and low area per minimum bandwidth and filter pole.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A method and an apparatus for signal processing: implementing step-by-step orthogonal decomposition of an original signal to be inputted; on the basis of the number of layers of orthogonal decomposition and the edge high frequency bandwidth of the original signal after orthogonal decomposition, generating a finite-length unit impulse response FIR filter; using the FIR filter to filter the edge high-frequency signal of the original signal; and, after passing the signal obtained after filtering and the low frequency signal obtained at each stage of orthogonal decomposition through an orthogonal filter bank, implementing signal synthesis processing.