Hitachi, Ltd.

Hitachi Denshi Kabushiki Kaisha

Hitachi Video and Information System, Inc.

Hitachi Communication System, Inc.

Toyoji Tabuchi

Mitsutaka Hikita

Nobuhiko Shibagaki

Kazuhito Kurosawa

Atsushi Sumioka

Atsushi Isobe

Tetsuya Hirashima

Hiroomi Kojima

Takatoshi Akagi

Hideo Zama

Yasuaki Kinoshita

Tomomi Matsumoto

Satoshi Wakamori

Tuneo Kinoshita

Sadao Nomura

Ryozo Murata

A high frequency module is disclosed which comprises a high frequency device in a package, a circuit formed on a flexible substrate in the package, the circuit, the high frequency device and input/output terminals of the package being connected electrically.

High frequency module including a flexible substrate

In a high frequency circuit device, inductive circuit elements constituting a matching circuit are constructed of so-called helical coils having fine metal wires wound in a hollow solenoid form, which are disposed inside a package in which a high frequency circuit element such as a surface acoustic wave element or the like is mounted. The high frequency circuit device may be utilized in equipment such as wireless communication equipment for reducing the size as well as providing good high frequency characteristics.

High frequency circuit device

A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the propagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other. Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.

Surface acoustic wave device

A surface acoustic wave device is disclosed for use in a communication apparatus where the surface acoustic wave device has a multiple of surface acoustic wave elements with different filter characteristics formed on mutually distinct piezoelectric substrates. The different filter characteristics combine to form filters having desired filter characteristics.

Surface acoustic wave filter device formed on a plurality of

Disclosed is a SAW filter employing a SAW resonator which is constructed of a plurality of pairs of electrode fingers formed on a piezoelectric substrate, and in which a plurality of SAW transmission spaces are included. The SAW transmission spaces do not have the function of exciting a SAW, and they have electric lengths which match the phases of SAWs excited by the resonator. In accordance with frequency characteristics required of the filter, such SAW transmission spaces are introduced into, for example, one of a plurality of SAW resonators located on the electric power input side of the filter.

Surface acoustic wave filter including saw resonators with transmission

At least one electro-acoustic transducer of a first surface acoustic wave device and acousto-electric transducers of a second surface acoustic wave device are arranged symmetrically to the first surface acoustic wave device about a line parallel to a propagating direction of surface acoustic wave and is phase-weighted differently from the remaining transducers having common phase-weighting, to improve an attenuation for stop frequency.

Surface acoustic wave band-pass filter with different phase weighted

A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the progagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other. Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.

A SAW resonator includes resonating SAW transducer units formed on a piezoelectric substrate and juxtaposed in a direction of propagation of acoustic waves, and a unidirectionally reflecting SAW transducer unit provided in each end of the juxtaposed resonating SAW transducer units on the substrate. Each resonating SAW transducer unit includes first and second SAW transducers connected in series and/or in parallel with each other. Each unidirectionally reflecting SAW transducer unit includes first and second comb-like electrodes having a plurality of first second fingers, respectively, formed on the substrate, in which: two second fingers are interposed between each pair of adjacent two first fingers; at least one reflective stripe is provided between the two second fingers interposed between at least one pair of adjacent two first fingers; and the distances between the reflective stripe and the two second fingers and the widths of the two second fingers are determined such that acoustic waves produced by the fingers of the reflecting SAW transducer units and propagating in a first direction perpendicular to the direction of the length of the fingers and reflected by the reflective stripe in a second direction perpendicular to the first direction are in phase with acoustic waves propagating in the second direction and acoustic waves produced by the fingers of the reflecting SAW transducer units and propagating in the second direction and reflected by the reflective stripe in the first direction are out of phase with acoustic waves propagating in the first direction.

SAW resonator having a broad bandwidth

A surface acoustic wave device has its inter--digital transducers made of a 3--metal alloyed material consisting of aluminum, copper and magnesium.

Electrode material for surface acoustic wave devices and surface

At least two frequencies, one on the higher frequency side and the other on the lower frequency side of a desired frequency, are selected from a predetermined set of frequencies, and stripe widths corresponding to the selected frequencies are combined to realize a desired average stripe width which is used to form an electrode structure of a SAW device. At least one electrode configuration of the SAW device includes an alternate arrangement of electrode stripe and free area stripe and the alternate arrangement is divided into a predetermined number of plural sections within each of which a ratio of the number of stripes of a first width to the number of stripes of a second width is set to a predetermined value. The electrode configuration can be prepared without resort to a highly precise mask and can permit highly precise setting of the center frequencies.

Electrode structure for saw device

A surface acoustic wave filter having transmitting and receiving transducers, coupling transducers, as well as reflecting transducers which are arrayed on a piezo-electric substrate. The coupling transducers are so designed as to function as 3-dB directional couplers in order to obtain frequency characteristics over a wide range without developing ripples.

Surface acoustic wave filter

A liquid crystal display panel is composed of a plate of ferroelectric material, a group of electrodes arranged in a first direction on one surface of the plate, a second group of electrodes arranged in a second direction orthogonal to the first direction on a second surface of the plate, dielectric films disposed on the first group of electrodes, intermediate electrodes the main part of which is situated on each of the dielectric films and the side part of which is situated on a second surface of the plate opposite each of the second group of electrodes. A transparent substrate is arranged opposite the second surface of the plate, a third group of electrodes are arranged on the transparent substrate opposite and parallel to each of the second group of electrodes and means is provided for connecting each of the second group of electrodes to each of the third group of electrodes which is opposite to the former, and a liquid crystal is interposed between the transparent substrate and the plate.

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Tsukui, Japan

Toyoji Tabuchi