Abstract: A surface acoustic wave device includes an electrode formed by a first film and a second film on a substrate, the first film including an Al film or a film formed by adding at least one other element to Al, and the second film including a metal whose coefficient of diffusion into Al is greater than a self diffusion coefficient of Al. The present invention contributes to improvement of the high-power durability of the electrodes.

Abstract: An oscillation circuit of phase-shift type includes a surface acoustic wave filter in a feedback circuit, the surface acoustic wave filter having first and second one-port surface acoustic wave resonators of different resonance frequencies connected in a ladder configuration. The oscillation circuit has a high C/N ratio with a large bandwidth of variable frequency and can be fabricated in a small size with low costs.

Abstract: A duplexer package comprises two surface acoustic wave filter chips having different band center frequencies and a phase matching circuit for matching the phases of the two SAW filter chips, the filter chips and the phase matching circuit being accommodated in one unit, wherein the phase matching circuit is formed in a layer providing a cavity for the filter chips, the layer defining the cavity being located above a face for mounting the surface acoustic wave filter chips. According to the present invention, the height of the duplexer package can be lowered.

Abstract: A SAW (Surface Acoustic Wave) device includes a piezoelectric member, a heat-treated ion implantation layer formed in a surface portion of the piezoelectric member, and an electrode of a comb type resonator with reflectors provided on said heat-treated ion implantation layer. The present invention also provides a method of producing such a SAW device.

Abstract: In a duplexer, phase matching circuit patterns corresponding to filter chips are formed on a surface layer of a multi-layer ceramic package provided with filter chips having different central frequencies. An end of each of the phase matching circuit patterns is connected to a common terminal pattern.

Abstract: This invention relates to a surface acoustic wave device and a production process thereof. An electrode is formed by alternately laminating a film of an aluminum alloy containing at least copper added thereto and a copper film on a piezoelectric substrate. While the particle size of the multi-layered electrode materials is kept small, the occurrence of voids in the film is prevented and life time of the surface acoustic wave device is elongated.

Abstract: This invention relates to a surface acoustic wave device and a production process thereof. An electrode is formed by alternately laminating a film of an aluminum alloy containing at least copper added thereto and a copper film on a piezoelectric substrate. While the particle size of the multi-layered electrode materials is kept small, the occurrence of voids in the film is prevented and life time of the surface acoustic wave device is elongated.

Abstract: A SAW filter includes a first SAW resonator having a pair of terminals and a predetermined resonance frequency (f.sub.rp), the first SAW resonator being provided in a parallel arm of the SAW filter. A second SAW resonator has a pair of terminals and a predetermined resonance frequency (f.sub.rs) approximately equal to a predetermined antiresonance frequency of the first SAW resonator (f.sub.ap). The second SAW resonator is provided in a series arm of the SAW filter. An inductance element is connected in series to the first SAW resonator.

Abstract: A multilayer duplexer package is provided, which includes: two surface-acoustic-wave filter chips having different center pass band frequencies; and at least two phase matching circuits for matching the phase of one filter chip to that of the other filter chip, said phase matching circuits respectively comprising strip lines stacked one above another, and said strip lines each having a characteristic impedance higher than the characteristic impedance of an external circuit to be connected to the duplexer package.

Abstract: A SAW filter includes a first SAW resonator having a pair of terminals and a predetermined resonance frequency (f.sub.rp), the first SAW resonator being provided in a parallel arm of the SAW filter. A second SAW resonator has a pair of terminals and a predetermined resonance frequency (f.sub.rs) approximately equal to a predetermined antiresonance frequency of the first SAW resonator (f.sub.ap). The second SAW resonator is provided in a series arm of the SAW filter. An inductance element is connected in series to the first SAW resonator.

Abstract: A surface acoustic wave device comprises a pair of multiple-electrode surface acoustic wave elements that are mirror-symmetrically arranged and disposed on a piezoelectric substrate. Each of the multiple-electrode surface acoustic wave elements comprises a plurality of input/output inter-digital transducers and connected inter-digital transducers. The number of the input/output inter-digital transducers is equal to or smaller by one, than the number of the connected inter-digital transducers, so that insertion loss of the surface acoustic wave device can be reduced without increasing the size of the device.

Abstract: A surface acoustic wave device in which a surface acoustic wave device element is arranged with interdigital electrodes on a piezoelectric substrate is packaged in a package provided in a metal pattern. Metal bumps are formed on a bonding pad section of the surface wave device element and the metal bumps are contact connected with the metal pattern of the package.

Abstract: A SAW device comprises a substrate, input and output interdigital electrodes provided on the substrate alternately to form a row of electrodes, and a pair of open strip reflectors disposed at both ends of the row, the input interdigital electrodes having a first pair number representing the number of pairs of opposing finger electrodes forming the input electrode, the output interdigital electrodes having a second pair number representing the number of pairs of opposing finger electrodes forming the output electrode, wherein the first pair number and second pair number are set different in the adjacent input and output electrodes with a predetermined ratio therebetween, the first pair number is changed in each input electrodes in the row, and the second pair number is changed in each output electrodes in the row.