A receiving apparatus includes a base-band conversion circuit, a synchronizing circuit/code generator and a demodulator. The base-band conversion circuit converts a received signal into a base-band signal. The synchronizing circuit/code generator detects a spread code included in the received signal to generate a plurality of spread codes in synchronization with the spread code included in the received signal. The demodulator uses the plurality of spread codes supplied by the synchronizing circuit/code generator to demodulate the base-band signal.

Spread spectrum receiving apparatus

The invention pertains to chiral compounds that contain at least one double or multiple bonded chiral group, at least one polymerizable group, at least one spacer and at least one mesogenic group, and to their use as polymerizable, chiral doping agents in the production of cholesteric networks. The compounds as per the invention can be used in electro-optical displays or as chiral doping agents for nematic or cholesteric liquid crystals to produce color-reflecting layers.

Polymerizable, chiral compounds and their use

The liquid crystal device is constituted by disposing a display layer between a pair of electrode plates. The display layer comprises a porous polymer material having open pores partially filled and a low-molecular weight mesomorphic compound impregnating the porous polymer material. The display layer is free from an unfilled portion of the low-molecular weight mesomorphic compound to be effective for providing a liquid crystal device showing a high transmittance and a good contrast. The display layer also comprises a three dimensional network structure coated with a polymer layer, and a low-molecular weight mesomorphic compound impregnating the three-dimensional network structure. The display layer is free from a fibrous part which is unstable against an applied voltage to be effective for providing a liquid crystal device showing no hysteresis.

Liquid crystal device, display apparatus using same and display method using same

Provided is a color filter which comprises a substrate and a resin layer on the substrate, the resin layer containing a plurality of colored portions of different colors and non-colored portions.

Method for manufacturing a color filter in which light irradiation alters the ink absorption of portions of a resin layer and in which coloring is done by ink jets

A surface acoustic wave (SAW) filter includes a piezoelectric substrate. A resin pattern having a permittivity less than that of the piezoelectric substrate and first and second conductor patterns are disposed on the piezoelectric substrate. The first conductor pattern defines two one-terminal-pair SAW resonators and two longitudinally coupled resonator SAW filters. A portion of the second conductor pattern defines wiring traces having different potentials. Portions of the wiring traces facing each other in a plan view are disposed on the resin pattern.

Surface acoustic wave filter and communication apparatus

A nonlinear optical material is provided by mixing a polymer liquid crystal having a chiral center and a nonlinear optical compound. The polymer liquid crystal may be a ferroelectric polymer liquid crystal. The nonlinear optical material is preferably in the form of a solid solution. A nonlinear optical device is formed by orienting the nonlinear optical material to provide an optical member.

Nonlinear optical material and nonlinear optical device

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 matched filter has an input IDT and an output IDT, and also has a device for preventing propagating surface acoustic waves from diverging. By preventing the divergence of surface acoustic waves, signals obtained in units of electrode finger pairs of the output IDT are uniformed. Furthermore, this application also discloses the following arrangement. That is, an arrangement for converging surface acoustic waves is adopted, and the width of surface acoustic waves input to the output IDT is set to be larger than at least the crossing width of electrode fingers, nearest to the input IDT, of those of the output IDT, so that some surface acoustic waves propagate along non-crossing portions of the electrode fingers, on the input IDT side, of those of the output IDT. With this arrangement, the influence of the crossing portions of the electrode fingers, closer to the input IDT, on the surface acoustic waves input to the crossing portions of the electrode fingers, farther from the input IDT, can be relaxed.

Matched filter with improved synchronous characteristics, and reception device and communication system using the same

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.

Surface acoustic wave element and communication system using the same

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.

Koichi Egara

Papers

Nonlinear optical material and nonlinear optical device

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

Matched filter with improved synchronous characteristics, and reception device and communication system using the same

Surface acoustic wave element and communication system using the same

Elastic surface wave convolva having wave width converting means and communication system using same