A multiplexer includes a filter located between a common terminal and an individual terminal, and a filter that is located between the common terminal and an individual terminal and that has a pass band whose frequency is lower than the pass band of the filter. The filter includes serial arm resonators provided on the first path connecting the common terminal to the individual terminal. Each of the serial arm resonators includes a piezoelectric substrate and an IDT electrode which use leaky waves as principal acoustic waves. The occurrence frequency of the Rayleigh wave response of the serial arm resonator is different from that of the serial arm resonator.

A composite substrate for an acoustic wave device includes a piezoelectric material layer, supporting substrate and x layers (x represents an integer of 3 or larger) of intermediate layers between the piezoelectric material layer and supporting substrate. The piezoelectric material layer, supporting substrate and intermediate layers satisfy a formula (1) (R.sub.n<R.sub.n+1), the formula (2) (V.sub.n−1<V.sub.n) is satisfied when x is an even number. A formula (3) (V.sub.n−1>V.sub.n) is satisfied when x is an odd number.

An cartridge is combined with a smart device which is capable of communicating with a network to perform a portable, fast, field assay of a small sample biological analyte. A closed microfluidic circuit for mixes the analyte with a buffer with functionalized magnetic beads capable of being specifically combined with the analyte. A detector communicates with the microfluidic circuit in which the mixed analyte, buffer and combined functionalized magnetic beads are sensed. A microcontroller is coupled to detector for controlling the detector and for data processing an output assay signal from the detector. A user interface communicates with the microcontroller for providing user input and for providing user output through the smart device to the network.

In at least one embodiment, the SAW device comprises a carrier substrate (1), a piezoelectric thin-film (2) on the carrier substrate, an interdigital electrode structure (3) on the piezoelectric thin-film and a layer stack (4) of waveguide layers. The layer stack is arranged between the carrier substrate and the piezoelectric thin-film. The layer stack comprises a first waveguide layer (41) and second waveguide layer (42), wherein a sound velocity in the first waveguide layer is at least 1.5 times as great as in the second waveguide layer. The device may comprise a temperature compensating layer (5) and a trap rich layer (6) between the layer stack and the carrier substrate.

A SAW resonator with reduced spurious modes is provided. The resonator comprises a (111) silicon carrier substrate (CS), an electrode structure (ES) and a piezoelectric layer (PIL). The carrier substrate has a crystal orientation with the Euler angles (−45°±10°; −54°±10°; 60°±30°) and the piezoelectric layer comprises LiTaO.sub.3 and has a crystal orientation with the Euler angles (0°; 56°±8°; 0°). There may be intermediate layers (IL1, IL2) of SiO.sub.2 and amorphous or polycrystalline materials. In addition a silicon nitride layer is provided as passivation (PAL). Electrodes are made of aluminum. Thicknesses of all layers are selected in particular ranges to optimize SAW behaviour.

An acoustic wave device includes a support substrate having a thickness in a first direction, a piezoelectric layer on the support substrate, and an interdigital transducer electrode on the piezoelectric layer and including first and second electrode fingers extending in a second direction crossing the first direction. The second electrode fingers face the first electrode fingers in a third direction orthogonal or substantially orthogonal to the second direction. The support substrate and the piezoelectric layer include a hollow therebetween at a position at least partially overlapping the interdigital transducer electrode in the first direction. At least one through hole penetrates the piezoelectric layer at a position not overlapping the interdigital transducer electrode in the first direction, and the through hole communicates with the hollow. A reinforcing support extends inside the hollow in a region overlapping the hollow and not overlapping the first and second electrode fingers.

An acoustic wave device includes a support substrate having a thickness in a first direction, a piezoelectric layer on the support substrate, an interdigital transducer electrode on the piezoelectric layer and including first and second electrode fingers, the first electrode fingers extending in a second direction crossing the first direction, the second electrode fingers extending in the second direction and facing the first electrode fingers in a third direction orthogonal or substantially orthogonal to the second direction, and a reinforcing film on the piezoelectric layer. The support substrate and the piezoelectric layer include a hollow therebetween at a position overlapping the interdigital transducer electrode in the first direction. At least one through hole penetrates the piezoelectric layer at a position not overlapping the interdigital transducer electrode in the first direction, and the through hole communicates with the hollow. The reinforcing film overlaps the hollow in the first direction.

An acoustic wave device includes a first piezoelectric layer that is a rotated Y-cut lithium tantalate substrate and has a first thickness, a second piezoelectric layer that is a rotated Y-cut lithium niobate substrate, is stacked on the first piezoelectric layer, has a second thickness that is less than the first thickness, and has a spontaneous polarization direction that is substantially opposite to a spontaneous polarization direction of the first piezoelectric layer, a first electrode provided on an opposite surface of the first piezoelectric layer from the second piezoelectric layer, and a second electrode that is provided on an opposite surface of the second piezoelectric layer from the first piezoelectric layer, at least a part of the first piezoelectric layer and at least a part of the second piezoelectric layer being interposed between the first electrode and the second electrode.

Guided Surface Acoustic Wave (SAW) devices with improved quartz orientations are disclosed. A guided SAW device includes a quartz carrier substrate, a piezoelectric layer on a surface of the quartz carrier substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the quartz carrier substrate. The quartz carrier substrate includes an orientation that provides improved performance parameters for the SAW device, including electromechanical coupling factor, resonator quality factor, temperature coefficient of frequency, and delta temperature coefficient of frequency.

A surface acoustic wave resonator arrangement comprises a piezoelectric substrate (100) and a surface acoustic wave resonator (110) which includes an interdigital transducer (111,112) disposed on the piezoelectric substrate (100). A trench (13 0) is disposed within the piezoelectric substrate (100) facing the resonator (110). Trench (130) causes reflected waves (143,144) in response to waves (141,142) leaking from the surface acoustic wave resonator. Trench (130) is configured such that the reflected acoustic waves (143,144) achieve phases at the edge (115) of the resonator (110) such that the accumulated phases of all the reflected waves received at edge (115) is zero or substantially zero, thereby avoiding constructive interference of the reflected waves with the acoustic waves resonating in the resonator. Thereby undesired acoustic coupling between resonators or influence of waves reflected at edges of the piezoelectric substrate or dicing lines is reduced.