A low power apparatus for measuring various process parameters and/or physical properties of a fluid or gas medium by measuring the change of a wave signal or time dependent signal as it traverses the fluid or gas medium, the apparatus comprising: at least one transmission transducer for providing a transmitted wave or time dependent signal for injection into the fluid or gas medium; at least one reception transducer, displaced from the transmission transducer for receiving a received wave or time dependent signal from the fluid or gas medium; and an analog signal processor, coupled to the reception transducer, for processing of the received wave or time dependent signal such that a short interval of the processed received wave or time dependent signal is extracted.

Low power signal processing and measurement apparatus

In order to reduce scattering losses during the transmission of a surface acoustic wave signal, a surface acoustic wave arrangement has a junction between two mutually offset surface acoustic wave structures designed so that the finger period is reduced in the region of the junction, and varies continuously in the region of the junction.

Surface acoustic wave arrangement with a junction region between surface acoustic wave structures having a decreasing then increasing finger period

A surface-acoustic-wave device comprises a piezoelectric substrate and first and second comb-shaped electrodes each having a bus-bar portion parallel to a propagation direction of a surface acoustic wave in the substrate. Respective electrode fingers are periodically formed on the piezoelectric substrate and extend in directions perpendicular to the propagation direction, wherein the electrode fingers of the first comb-shaped electrode and the electrode fingers of the second comb-shaped electrode are separated away from the bus-bar portion of the opposing comb-shaped electrode. The respective electrode fingers being periodically arrayed in the propagation direction of the surface-acoustic-wave, and the electrode fingers of each comb-shaped electrode are inclined at root portions thereof outwardly right and left from the bus-bar portion of the corresponding comb-shaped electrode so that the inclined portions of the electrode fingers face a direction of a leaking surface-acoustic-wave perpendicularly.

Surface Acoustic Wave Device

A unidirectional surface acoustic wave (SAW) transducer has a substrate which is piezoelectric or electrostrictive, a first IDT (interdigital transducer) electrode disposed on a surface of the substrate and having a plurality of first electrode fingers, and a second IDT electrode disposed on the surface of the substrate and having a plurality of second electrode fingers alternating with the first electrode fingers, and structural elements disposed on the surface of the substrate and arranged periodically in a propagating direction of surface acoustic waves. The structural elements comprise grooves or dielectric films each having a width of λ 0 /4 or λ 0 /2, for example, where λ 0 represents a wavelength corresponding to a fundamental operating frequency of the unidirectional surface acoustic wave transducer.

Surface acoustic wave transducer

A surface acoustic wave device includes a piezoelectric substrate, a wave guide path provided on the piezoelectric substrate and an interdigital transducer for exciting a surface acoustic wave. The interdigital transducer is provided with plural portions of mutually different pitches of the electrode finger, respectively corresponding to different frequencies. The portions are parallelly arranged along a direction perpendicular to the propagation direction of the surface acoustic wave. The surface acoustic wave generated by the interdigital transducer is entered in concentrated manner into the wave guide path.

Efficient surface acoustic wave device capable of excitation in plural frequency bands, and signal receiver and communication system utilizing the same

A surface acoustic wave convolver includes first and second interdigital electrodes for exciting surface acoustic waves and an output electrode for detecting the surface acoustic waves to extract a convolution output as an electrical signal, the first and second interdigital electrodes and the output electrode being formed on a piezoelectric or electrostrictive substrate. In order to improve convolution efficiency and obtain wide-range characteristics, each of the first and second interdigital electrodes has a predetermined thickness, the first interdigital electrode is arranged such that positive and negative electrodes are alternately arranged so as to have electrode widths and periods which are gradually decreased toward the output electrode, the second interdigital electrode is arranged such that positive and negative electrodes are alternately arranged so as to have electrode widths and periods which are gradually increased toward the output electrode, and the second interdigital electrode has a double electrode structure in addition, in order to reduce ripples in frequency characteristics, the output electrode are divided into a plurality of pieces, and two end portion of each of the first and second interdigital electrodes are weighted.

Norihito Mihota

Papers

Surface acoustic wave convolver