Phase shift circuits including two or more slanted-finger IDT electrodes, and filters, duplexers, or other electronic devices incorporating same. In one example a filter includes a main filter circuit connected between an input and an output and having a first phase characteristic, and a phase shift circuit connected in parallel with the main filter circuit, the phase shift circuit including first and second capacitor elements and a pair of acoustic wave elements connected in series between the first and second capacitor elements, the pair of acoustic wave elements including a pair of slanted-finger IDT electrodes disposed apart from each other on a single acoustic wave path along which acoustic waves propagate through the acoustic wave elements, the phase shift circuit having a second phase characteristic opposite to the first phase characteristic in an attenuation band that corresponds to at least a portion of a stopband of the main filter circuit.

An electro-acoustic transducer and an electro-acoustic component including an electro-acoustic transducer are disclosed. In an embodiment the transducer includes a first and a second bus bar, a plurality of electrode fingers and a plurality of two or more sub tracks, wherein each electrode finger is electrically connected to one of the bus bars, wherein each sub track extends along a longitudinal direction, wherein all sub tracks are arranged one next to another in a transversal direction, wherein at least a first of the sub tracks includes segments of the electrode fingers and has an associated sub track with segments of the electrode fingers, wherein the segments of the electrode fingers of the first sub track are shifted by a distance S=/2 along the longitudinal direction relative to the segments of the electrode fingers of the associated sub track, and wherein is an acoustic wavelength.

An input port, an output port, and a plurality of serial resonators and a plurality of parallel resonators connected in a ladder type between the input port and the output port and including IDT electrodes are provided. The plurality of parallel resonators include at least one first parallel resonator having a resonance frequency lower than resonance frequencies of the plurality of serial resonators, and at least one second parallel resonator having a resonance frequency higher than antiresonance frequencies of the plurality of serial resonators.

An elastic wave resonator including a pair of comb-shaped electrodes and a pair of reflector electrodes formed on a piezoelectric substrate. In one example, the pair of comb-shaped electrodes includes first and second overlapping regions in which electrode fingers of the comb-shaped electrodes interdigitate, the second overlapping region being provided on both outside edges of the first overlapping region in an overlapping width direction, an overlapping width of the first overlapping region being greater than an overlapping width of the second overlapping region, the pair of comb-shaped electrodes being configured to excite a first elastic wave in the first overlapping region and to excite a second elastic wave in the second overlapping region, a frequency of the first elastic wave being higher than a frequency of the second elastic wave.

In a filter device, a transversal elastic wave filter, which defines a delay element, is connected in parallel with a band pass filter. The transversal elastic wave filter has the same amplitude characteristic as and the opposite phase to the band pass filter at a desired frequency inside an attenuation range of the band pass filter. When a wavelength determined by an electrode finger period of IDTs and is denoted by , the distance between the first IDT and the second IDT of the elastic wave filter is about 12 or less.

Improved surface acoustic wave structures (or elements) that can be used to realize any of a wide variety of dispersive or non-dispersive transversal SAW filters that are distinct from prior known means for producing such filters are disclosed. The devices and structures may include stepped acoustic wave delay modification elements that can be used to implement transversal filter impulse response functions in a manner analogous to the use of interdigital transducers. The structures disclosed are of particular usefulness to implement SAW devices at high frequencies where normal photolithographic resolution would prove limiting. Aspects and embodiments of the present invention would be useful to produce SAW devices for use in a wide variety of applications, including as components in cell phones, in radar and other communications and electronic systems, and as wired or wireless sensors or sensor-tags.

A filter working with surface acoustic waves comprises a piezoelectric substrate (SU), a first transducer (IDT1) arranged in the acoustic track coupled to an input, having a first mean finger period (pi) assigned to a center frequency of a pass band of the filter and a second transducer (IDT2) arranged in the acoustic track coupled to an output, having the same first mean finger period (p1), and a reflector arranged between first and second transducer having a second mean finger period (p2) assigned to a stop band frequency different from the center frequency. Further, a new type of very broad bandwidth filters with small insertion loss and high return loss and high rejection are given that use a substrate that can propagate a PSAW and comprises fan shaped transducers.

An elastic wave resonator including comb-shaped electrodes and reflector electrodes formed on a piezoelectric substrate. In one example, an overlapping portion between the comb-shaped electrodes includes a first overlapping region and second overlapping regions. The second overlapping regions can be provided on both outside edges of the first overlapping region. In one example, the overlapping width of the first overlapping region is greater than the overlapping width of the second overlapping region, and the electrode finger pitch in the second overlapping region is greater than the electrode finger pitch in the first overlapping region.

An acoustic wave device includes: a piezoelectric substrate; and an IDT formed on the piezoelectric substrate, wherein an anisotropy coefficient is positive, an overlap region where electrode fingers of the IDT overlap each other includes a center region and an edge region, the electrode fingers in the center and edge regions are continuously formed, the electrode finger in the edge region is inclined with respect to the electrode finger in the center region so that a pitch in a width direction of the electrode finger in the edge region is greater than a pitch in a width direction of the electrode finger in the center region, and an angle between the width direction in the center region and a crystal axis orientation of the piezoelectric substrate is less than an angle between the width direction in the edge region and the crystal axis orientation.

In a filter device, a transversal elastic wave filter, which defines a delay element, is connected in parallel with a band pass filter. The transversal elastic wave filter has the same amplitude characteristic as and the opposite phase to the band pass filter at a desired frequency inside an attenuation range of the band pass filter. When a wavelength determined by an electrode finger period of IDTs and is denoted by , the distance between the first IDT and the second IDT of the elastic wave filter is about 12 or less.