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Patent

Surface acoustic wave waveguide-coupled resonator notch filter

Sunder G. Gopani, +1 more
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TLDR
In this paper, a surface acoustic wave (SAW) waveguide-coupled resonator filter is over-coverage to produce an essentially constant conductance and susceptance over at least the bandwidth of a desired notch filter.
Abstract: 
A surface acoustic wave (SAW) waveguide-coupled resonator filter is overcoupled to produce an essentially constant conductance and susceptance over at least the bandwidth of a desired notch filter. The SAW resonator filter is embedded in a bridged-T allpass circuit to provide the pair of equal capacitances of the circuit, and the resonator ground is connected to one terminal of the parallel inductor of the circuit having the other terminal connected to a system ground.

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Citations
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PatentDOI

Surface-acoustic-wave filter

Yoshio Satoh, +4 more
- 27 Oct 1992 - 
TL;DR: In this article, a SAW filter comprising a piezoelectric substrate and at least two filter tracks formed on the substrate, each having at least 2 IDT electrodes for input and output, is presented.
Patent

Band reject filters

Steve Beaudin, +2 more
TL;DR: In this article, a band reject filter overcomes the insertion loss and power handling limitations of conventional band pass configurations and as such can be used in power amplifier and duplexer applications.
Patent

Filter having resonators coupled by a saw filter and a duplex filter formed therefrom

Aimo Turunen, +1 more
TL;DR: In this article, the SAW filter and the amplifier are inductively or capacitively coupled to the resonators depending upon the type of filter that is required, and if three or more resonators are present in the first filter then an amplifier can also be integrated in the filter.
Patent

Resonant circuit, filter, and antenna duplexer

Shogo Inoue, +3 more
TL;DR: In this article, the authors provided a resonant circuit consisting of a resonator, an inductor connected in parallel with the resonator and a capacitated capacitor connected at the same time.
Patent

Method and apparatus for an acoustic wave filter

Thomas S. Hickernell, +1 more
TL;DR: In this article, a low-loss acoustic wave filter includes a piezoelectric substrate, a first strongly unidirectional acoustic wave transducer and a second strongly unideal acoustic beamforming transducers.
References
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Patent

Surface acoustic wave filter

Takaya Watanabe, +1 more
TL;DR: In this article, a surface acoustic wave (SAW) filter has a piezoelectric substrate and a conductive transducer formed over the substrate, and the transducers have first and second bus bars arranged in parallel at a prescribed interval from each other.
Patent

Filter combining surface acoustic wave resonators

Mitsutaka Hikita, +2 more
TL;DR: In this article, a band-pass or band-rejection filter is constructed by combining a plurality of one-port surface acoustic wave resonators whose interdigital electrode fingers are disposed on a piezoelectric substrate.
Patent

Surface acoustic wave filter

Yuji Fujita, +9 more
TL;DR: In this article, the authors proposed a cascaded multiplex mode surface acoustic wave filter with small insertion loss in a passband and with a wide passband, where three interdigital electrodes (IDTs) are closely provided along the propagation direction of exciting surface acoustic waves on a piezoelectric substrate, and reflectors are provided on both sides of the series of IDTs, thereby providing 3IDT cascaded duplex mode filters utilizing at least a primary or third-order oscillation mode generated by acoustic coupling among the three IDTs.
Patent

Acousto-electric filter utilizing surface wave propagation in which the center frequency is determined by a conductivity pattern resulting from an optical image

Robert Adler, +1 more
Patent

High frequency narrow-band multi-mode filter

Yuzo Nakazawa, +4 more
TL;DR: In this paper, a high frequency narrowband pass multi-mode filter was constructed in such manner that SAW of SSBW resonators were closely disposed to each other on a single piezo-electric substrate to generate different vibration modes of different resonance frequencies, conditions that the resonators are acoustically coupled to each another to cause these vibration modes, were experimentally found, and the above conditions are satisfied by the filter.