摘要:
In a surface acoustic wave elastic convolver capable of showing sufficiently high convolution efficiency with a simple structure, the convolver comprises a piezo-electric substrate, plural input transducers formed on the substrate for respectively generating surface acoustic waves corresponding to input signals, an output transducer for obtaining a convolution signal of the input signals, from a surface acoustic wave generated by non-linear interaction, of the surface acoustic waves generated by those input transducers, and a dielectric film of a non-linear effect larger than that of the substrate, formed on the substrate in at least an area where the output transducer is formed.
摘要:
A surface acoustic wave device includes a piezoelectric substrate, first and second input transducers formed on the substrate and adapted for respectively generating surface acoustic waves corresponding to input signals, the first and second input transducers each having a shape to focus the surface acoustic waves generated thereby, an output transducer formed between the first and second input transducers on the substrate and adapted for obtaining a convolution -signal of the surface acoustic waves generated by the first and second input transducers, and conductive films, one formed between the first input transducer and the output transducer and another between the second input transducer and the output transducer on the substrate. A communication system includes a transmitter for transmitting a signal modulated according to information, a circuit for receiving the modulated signal transmitted from the transmitter, a circuit for generating a reference signal, a surface acoustic wave device, as described above, for outputting a convolution signal of the modulated signal and the reference signal, and a demodulating circuit for restoring the information, using the convolution signal output from the surface acoustic wave device.
摘要:
A surface acoustic wave device includes a substrate having piezoelectricity, at least two input electrodes, provided on the substrate, for exciting first and second surface acoustic waves, and an output electrode for taking a convolution signal of the two surface acoustic waves out. The substrate has a roughness configuration on a back face thereof and a maximum depth of the roughness configuration is not less than a wavelength of bulk waves of convolution output taken out of the output electrode.
摘要:
A surface acoustic wave device comprises a substrate, a plurality of input transducers formed on the substrate for generating first and second surface acoustic waves propagating in opposite directions to each other, and a plurality of waveguides arranged in a direction orthogonal to the propagating direction of the first and second surface acoustic waves on a region where the first and second surface acoustic waves overlap. Each waveguide producing a third surface acoustic wave propagating in a direction where the waveguides are arranged, with the interaction between the first and second surface acoustic waves, and on at least two of the waveguides, third surface acoustic waves reflected at respective side edges cancel each other, and an output transducer converts the third surface acoustic waves propagating from the waveguides into an electrical signal.
摘要:
An elastic surface wave convolve comprises a piezoelectric substrate, a plurality of input transducers formed on said substrate for generating elastic surface waves corresponding to respective input signals, a plurality of waveguides provided side by side on a region of the substrate where elastic surface waves radiated from the input transducers overlap, wherein a convolution signal of input signals is produced due to parametric mixing effect of elastic surface waves in respective waveguides, these waveguides generating an elastic surface wave corresponding to the convolution signal, and an output transducer for receiving the elastic surface wave radiated from the waveguides and taking out an electrical signal by conversion of the convolution signal, wherein the width of elastic surface wave radiated from the waveguides is narrower immediately before reception with the output transducer than immediately after radiation from the waveguides.
摘要:
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.
摘要:
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.
摘要:
A surface acoustic wave element is provided with a piezoelectic substrate, a first input transducer, a second input transducer and an output device such as output electrode. The piezoelectric substrate has a first and a second surfaces which are mutually faced. The first input transducer is formed on the first surface of the substrate to generate a first surface acoustic wave which propagates in a predetermined direction. The second transducer is formed on the first surface of the substrate to generate a second surface acoustic wave which propagates in a direction opposite to the predetermined direction. The output device is formed on the first surface of the substrate to extract a signal produced by an interaction of the first and second surface acoustic waves. At least part of the second surface of the substrate is caused to be inclined in a direction perpendicular to the predetermined direction with respect to the first surface.
摘要:
A surface acoustic wave device comprises a piezoelectric substrate, a plurality of input transducers, formed on the substrate, for generating surface acoustic waves corresponding to input signals, a plurality of waveguides which are juxtaposed on a region of said substrate where the surface acoustic waves generated by said input transducers overlap each other, and in which signals are generated due to an interaction of the surface acoustic waves, the waveguides generating surface acoustic waves corresponding to the signals due to the interaction, and an output transducer for receiving the surface acoustic waves generated from the waveguides, converting the signals due to the interaction into electrical signals, and extracting the electrical signals, the output transducer being constituted by a plurality of portions, juxtaposed in a widthwise direction of the surface acoustic waves generated from the waveguides, for receiving some components of the surface acoustic waves generated from the waveguides, and outputting signals, the portions being connected to each other, so that electric fields of electrical signals output from said portions are synthesized in the same direction.
摘要:
In a communication apparatus of the transmitting side, n number of parallel signals are respectively spread-modulated by the n number of spreading codes and summation thereof is obtained. Also, m number of parallel signals are respectively spread-modulated by the m number of spreading codes and summation thereof is obtained. These two signals are modulated with quadrature carriers, synthesized and transmitted to the receiving side.