Hitachi Media Electronics Co., Ltd.

Hitachi, Ltd.

Kazuyuki Sakiyama

Mitsutaka Hikita

Nobuhiko Shibagaki

Atsushi Isobe

Kengo Asai

Osamu Hikino

Ryo Suzuki

Ryo Imura

Kunio Matsumoto

Chisaki Takubo

Shinichi Fujiwara

Naoki Matsuura

Masato Kijima

Kohji Oda

Yoshinori Hoshina

A surface acoustic wave device in the present invention is provided with a piezoelectric substrate, a supporting substrate being jointed to the piezoelectric substrate and including a material different in expansion coefficient from the piezoelectric substrate and an interdigital electrode for exciting a surface acoustic wave, the electrode being arranged on the surface of the piezoelectric substrate. Either the interdigital electrode or the piezoelectric substrate is configured so that the interdigital electrode is 40% or more to 70% or less as long as the piezoelectric substrate in the direction to which a surface acoustic wave propagates.

Surface acoustic wave device and communication terminal using the same

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

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 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 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

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.

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Chigasaki, Japan

Kazuyuki Sakiyama