Hitachi, Ltd.

Hitachi Media Electronics Co., Ltd.

Hitachi Denshi Kabushiki Kaisha

Hitachi Video and Information System, Inc.

Hitachi Video Engineering, Incorporated

Hitachi Communication System, Inc.

Hitachi Denshi Kabushiki

Mitsutaka Hikita

Nobuhiko Shibagaki

Toyoji Tabuchi

Atsushi Isobe

Kazuhito Kurosawa

Kengo Asai

Atsushi Sumioka

Kazuyuki Sakiyama

Hisanori Matsumoto

Naoki Matsuura

Chisaki Takubo

Osamu Hikino

Tetsuya Hirashima

Shigeki Matsuda

Yoshikatu Ishida

Kazuyuki Yokoyama

Takatoshi Akagi

Ryo Suzuki

Yukio Ito

Hiroshi Takeuchi

Ryo Imura

Yoshio Abe

Kazuyuki Nagatsuma

Yasuaki Kinoshita

Sakichi Ashida

Yutaka Chiba

Tomomi Matsumoto

Kunihiro Hamada

Hiroomi Kojima

Satoshi Wakamori

Yoichi Saigo

Tuneo Kinoshita

Kohji Oda

Yoshinori Hoshina

Masato Kijima

Shigeru Jyo Mura

A technology which can realize a high-performance multiband operation in a compact circuit configuration and is advantageous for a wireless terminal of GSM system for which the further increase of the demands is expected in the future is provided. Provided is a multiband switch type antenna duplexer adopted in a mobile phone used in TDMA system such as the GSM system, in which the signals of respectively different first to fourth frequency bands (GSM 850, EGSM, DCS, PCS) share a single antenna, wherein switching elements such as receive filters and diodes are combined in various ways to perform the high-performance band switch with the minimum number of switching elements. The circuit of this antenna duplexer can realize not only the size reduction of the multiband switch antenna duplexer but also the size reduction and performance improvement of the wireless terminal itself.

Antenna duplexer and wireless terminal using the same

A piezoelectric thin film resonator is formed on a base substrate such as made of Si in which the resonance frequency is substantially determined by the lateral size not by the thickness of the resonator, whereby a resonator for use in TCXO, etc. is provided by the thin film technique, which enables to reduce the thickness of the film and the size of the resonator and integration with Si-based IC incorporating the resonator in one identical substrate.

Piezoelectric thin film resonators

A compact, inexpensive antenna sharing device meeting requirements in terms of transmitter distortion characteristic and ESD characteristic is provided which separates and combines signals transmitted and received in first to third signal bands and which thereby enables an antenna terminal to be shared as a common terminal. It includes a diplexer realizing an attenuation characteristic for protection against ESD, a compound semiconductor switch with an IIP3 of 66 dBm or more, and an inexpensive PIN diode switch.

Antenna sharing device and wireless communication terminal using the same

The present invention provides a film bulk acoustic wave resonator (FBAR) filter that can keep the Q factor high. The FBAR filter comprises a first FBAR with a first resonant frequency and a second FBAR with a second resonant frequency, formed on a same substrate. The FBAR filter has such a structure that a first underlayer is formed between the substrate and a first bottom electrode layer and a second underlayer is formed between the substrate and a second bottom electrode layer, the first underlayer thickness being different from the second underlayer thickness.

Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator

A resonator is connected in parallel to at least one serial-arm-connected resonator in a resonator type filter having a serial arm and a parallel arm. At this time, the resonance frequency of the resonator connected in parallel is set to be substantially the same as the resonance frequency of the parallel-arm-connected resonator. This makes it possible to prevent the deterioration of attenuation levels at the lower-frequency side of the filter, caused by an increase in the resistance of a connection element due to an increase in packaging density.

Resonator type filter

A bulk acoustic wave resonator in which the problem of the technology for forming the diaphragm structure is resolved, which is more compact and improved the frequency accuracy, and the manufacturing method thereof, a filter using the same, a semiconductor integrated circuit device using the same, and a high frequency module using the same are provided. The bulk acoustic wave resonator according to the present invention comprises a substrate having a first surface and a second surface opposite to the first surface, and a staked resonator including a first electrode film in contact with the first surface, a piezoelectric film overlaying the first electrode film and a second electrode film overlaying the piezoelectric film. The substrate is provided with an air gap including a first aperture opening at the first surface and a second aperture opening at the second surface at the position corresponding to the staked resonator, respectively and having air gap generally vertical shape to the first surface, and another air gap having a tapered shape in the vicinity of the first surface.

Bulk acoustic wave resonator and manufacturing method thereof, filter using the same, semiconductor integrated circuit device using the same, and high frequency module using the same

An antenna duplexer is reduced in size, so that a dual-band/triple-band mobile radio terminal small in size and light in weight is realized. An off-set PLL modulation system is adopted, and a transmitting system of the antenna duplexer is constituted by switches. Further, in mounting an SAW filter, a multi-layer substrate is adopted, matching circuits and so on are formed by lumped-constant circuit elements, and the SAW filter is received in a space provided on the multi-layer substrate.

Mobile radio terminal and surface acoustic wave antenna duplexer

A radio frequency filter that can be miniaturized is provided. The radio frequency filter has a ladder-type resonator filter, a first terminal, a second terminal, a serial capacitance, a parallel capacitance, a serial inductance, and a parallel inductance. In the ladder-type resonator filter, a plurality of first surface acoustic wave resonators or first film bulk acoustic resonators are connected in a ladder circuit configuration. The serial inductance and the parallel capacitance are connected between the ladder-type resonator filter and the first terminal. The serial capacitance and the parallel inductance are connected between the ladder-type resonator filter and the second terminal.

Radio frequency filter, radio frequency circuit, antenna duplexer and radio terminal

A surface acoustic wave antenna duplexer constituted by a transmitter-line filter, a receiver-line filter and an antenna terminal, the transmitter-line filter and the receiver-line filter being connected in parallel with the antenna terminal as a common terminal; wherein at least one of the transmitter-line and receiver-line filters includes a top filter using the whole of a transmitter band or a receiver band as its pass band, a surface acoustic wave resonator filter, and a transmitter or receiver terminal, the top filter, the surface acoustic wave resonator filter and the transmitter or receiver terminal being disposed in this order viewed from the antenna terminal, the surface acoustic wave resonator filter including at least one additive capacitance or inductance; and wherein a switching element is provided for varying a value of the capacitance or inductance so as to provide a function for varying a pass band frequency or an attenuation band frequency of the surface acoustic wave resonator filter.

Band-switchable surface acoustic wave antenna duplexer and mobile radio terminal

A surface acoustic wave device which includes a piezoelectric substrate, and an interdigital transducer formed on a planar surface of the piezoelectric substrate, and having first and second bus bars, a first plurality of electrode fingers connected to the first bus bar, and a second plurality of electrode fingers connected to the second bus bar. The first and second plurality of electrode fingers of the interdigital transducer have an electrode cross region in which the first and second plurality of electrode fingers are arranged alternatively. Each boundary between the first and second bus bars and a grating region of the first and second plurality of electrode fingers is arranged such that the boundary is not substantially parallel, with a transmission direction of surface acoustic waves excited by the interdigital transducer.

Surface acoustic wave device capable of suppressing spurious response due to non-harmonic higher-order modes

A surface acoustic wave signal processing apparatus for processing first and second high-frequency signals having frequencies f.sub.1 and f.sub.2 respectively, which comprises: first and second surface acoustic wave delay elements for receiving the first and second high-frequency signals respectively and independently of each other, the delay elements being formed as surface acoustic wave excitation and reception transducers on a piezoelectric substrate so that a phase delay .phi..sub.1 with respect to the frequency f.sub.1 is substantially equal to a phase delay .phi..sub.2 with respect to the frequency f.sub.2 (that is, .phi..sub.1 .apprxeq..phi..sub.2); and a mixer for mixing first and second high-frequency output signals of the first and second surface acoustic wave delay elements so that a signal having a frequency .vertline.f.sub.1 -f.sub.2 .vertline. which is a difference between the two frequencies f.sub.1 and f.sub.2 is taken out as an output signal of the mixer.

CDMA communication RF signal processing apparatus using SAW

Aluminum is used for the interdigital transducer mounted on a piezoelectric substrate to realize a surface acoustic wave transducer having a small capacity ratio, no spurious resonance, and a low loss. A .theta. rotated Y cut lithium niobate single crystal piezoelectric substrate is used for the piezoelectric material, a metal film of which principal ingredient is aluminum is used for the interdigital transducer, the direction of the interdigital transducer is made parallel to the X-axis of the lithium niobate single crystal, and thick h and electrode pitch P of the interdigital transducer have the following relationship:

Surface acoustic wave equipment

Without increasing propagation loss or diffraction loss, (unlike conventional surface acoustic wave, SAW, filters which need many electrode finger pairs for constructing interdigital transducers, IDTs, to realize a steep cutoff frequency characteristic by conventional weighting or apodization that involves a high propagation loss and a high diffraction loss), there is provided a SAW filter with a very steep cutoff frequency characteristic on the low frequency side which uses three IDTs having N1, N2 and N3 electrode finger pairs, respectively. The filter is particularly applicable to a mobile radio communication device, such as a cellular radio. The relation between all the number of pairs N1+N2+N3 of the IDTs and the electromechanical coupling coefficient k.sup.2 of the piezoelectric substrate is N2&lt;(N1+N3)&lt;3.times.N2, and 2/k.sup.2 .gtoreq.(N1+N2+N3).gtoreq.0.8/k.sup.2.

Structure of surface acoustic wave filter

A mask structure has two (or more) groups of device patterns formed on one transparent support plate. Each of the device patterns has a transparent partial pattern. One or both of the groups of device patterns are provided with phase shifting patterns for improvement of the resolution in the lithography. The transparent partial pattern in each of the device patterns in each of the device pattern groups is determined such that each of the transparent partial patterns held by one of the device pattern groups is adapted for combination with one transparent partial pattern held by the other device pattern group by two or more times of transmission of an exposure beam through the mask structure. Manufacturing of solid-state devices is possible by use of the mask structure, in which exposure of a photo-sensitive film on a substrate to an exposure beam through the mask structure is repeated two or more times with a relative position between the mask structure and the substrate being changed.

Mask structure having phase shifting pattern suitable for forming fine

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.

Growing community of inventors

Hachioji, Japan

Mitsutaka Hikita