Abstract: A three electrode type SAW longitudinal coupling filter includes a piezoelectric substrate having an electromechanical coupling factor (K.sup.2) higher than 10% and, three sets in total of input electrodes and output electrodes. Each of the electrodes includes a plurality of a electrode fingers of comb shape and are formed on the piezoelectric substrate. Reflectors are disposed at opposite sides of the input electrodes and output electrodes. The number of pairs of electrode fingers of the input electrodes is differentiated from the number of pairs of electrode fingers of the output electrodes. By the above arrangement, a large pass-band width can be obtained with small ripples and with an increase of the attenuation amount outside the band region.

Abstract: This invention provides a surface acoustic wave device mounted module which is miniature, light, and highly reliable. The surface acoustic wave device mounted module also has excellent frequency characteristics. The surface acoustic wave device mounted module includes a multilayer substrate which has at least one layer of a shield pattern, input-output electrodes, grounding electrodes, through holes used for connecting electrodes, and a surface acoustic wave element. The surface acoustic wave element has metallic bumps, which are transfer-coated with a conductive resin, on electrode pads and an insulating resin around the surface acoustic wave element. The electrode pads are input-output terminals and grounding terminals formed on the surface acoustic wave element. Continuities between the input-output terminals and the input-output electrodes, and between the grounding terminals and the grounding electrodes are established by the through holes.

Abstract: A surface acoustic wave device includes: a holding substrate; a piezoelectric substrate; an interdigital transducer formed on the holding substrate; and supports for holding said piezoelectric substrate on the holding substrate so that the interdigital transducer is evenly in contact with the piezoelectric substrate.

Abstract: In a surface acoustic wave-semiconductor composite device such as a surface acoustic wave convolver, a piezoelectric plate and a semiconductor plate are layered directly or with a gap between them. Input electrodes are provided to apply a plurality of input signals to the piezoelectric plate to excite surface acoustic waves, while an output electrode is provided to detect a convolution output signal of a change in electric potential of the semiconductor plate at an interface of the semiconductor plate with the piezoelectric plate. In the layered structure, the semiconductor plate is bonded directly to the piezoelectric plate by hydrogen bonds between hydroxyl groups or by covalent or ionic bonds of oxygen atoms with component atoms of the piezoelectric and semiconductor plates. In modified structures, an inorganic thin film is applied to one of the piezoelectric and semiconductor plates, while the inorganic thin film is bonded directly to the other of the two plates.

Abstract: A surface acoustic wave device includes: a single crystal piezoelectric substrate; a single crystal piezoelectric thin plate formed on the single crystal piezoelectric substrate, the single crystal piezoelectric thin plate being bonded to the single crystal piezoelectric substrate by direct bonding; and interdigital transducers formed on the single crystal piezoelectric thin plate, for exciting a surface acoustic wave in at least the single crystal piezoelectric thin plate.

Abstract: A high frequency ceramic multi-layer substrate includes a stripline embedded between two dielectric layers having ground electrodes at the top surface and at the bottom surface thereof and an electric circuit formed on another dielectric layer applied to one of the ground electrodes. The stripline is connected to the electric circuit through via holes provided through the dielectric layers. The equivalent length from the stripline to the electric circuit is a fourth of the wavelength of an input high frequency signal, to result in a high frequency attenuation circuit. Another high frequency ceramic multi-layer substrate further includes another electrode provided via another dielectric layer of larger dielectric constant to form a capacitor with one of the ground electrodes, and another dielectric layer for forming an electric circuit thereon is applied to the electrode. The stripline is connected to the electric circuit through via holes provided through dielectric layers.

Abstract: In a matching circuit for a high-frequency transistor, using a microstrip line for the main line and having a high-frequency transistor side main line shaped in a taper form, a thin-film capacitor and a grounding circuit are disposed between the taper part and the ground. The length of the parts of the thin-film capacitor is different in the signal traveling directions or the shape of the grounding circuit is different so that the impedance is matched at the output position of the thin-film capacitor part, while the spatial phase difference of high-frequency signals can be compensated at the same time.

Abstract: A thin-film capacitor which has excellent withstand voltage characteristic, dielectric loss characteristic and production yield can be obtained by forming its dielectric film with a 3-layered structure comprising a first silicon oxide film formed on a polycrystalline sintered body substrate by a chemical vapor-phase deposition method, a second silicon oxide film formed by coating on the first silicon oxide film a solution state silicon oxide precursor followed by denaturing by heat treatment, and a third silicon oxide film formed on the second silicon oxide film by a chemical vapor-phase deposition method. A hybrid microwave integrated circuit is manufactured in which the above-mentioned thin-film capacitors are used as input/output coupling and DC blocking capacitors, bypass capacitors and impedance matching capacitors.