Abstract: A surface acoustic wave (SAW) resonance device includes a SAW resonator formed on a piezoelectric substrate and including driving electrodes formed in a comb-like shape and reflectors arranged in both sides of the driving electrodes, and at least one capacitor formed on the piezoelectric substrate and electrically connected to the driving electrodes. A capacitance of the capacitor is set to be a specific value in accordance with a manner of connection of the capacitor to the SAW resonator. By the constitution, it is possible to simply and precisely carry out a frequency adjustment of the SAW resonance device. It is also possible to suppress occurrence of undesirable ripples or spurious signals to thereby obtain electric characteristics equivalent to those obtained in the case where the number of pairs of driving electrodes is increased.

Abstract: A surface acoustic wave (SAW) filter includes a plurality of interdigital transducers located on a piezoelectric substrate along a surface wave propagation direction, at least a single one-port SAW resonator connected in series with an output side of the SAW filter, while the resonance frequency of the SAW resonator is set at a level which is higher than the passband of the SAW filter.

Abstract: A resonator consists of an external conductor (1), a dielectric plate (2), a resonance capacity element, an input terminal (5), and an output terminal (6). The dielectric plate (2) is fixed at its upper and lower ends to the upper and lower walls, respectively, of the external conductor (1). The resonance capacity element is composed of electrodes of a metal thin layer or a metal plate provided on the front and back of the dielectric plate (2). The lower end of one of the electrodes is electrically connected to the lower wall of the external conductor (1), and a gap is formed between the upper end of the electrode and the upper wall of the external conductor (1), while the upper end of the other electrode is electrically connected to the upper wall of the external conductor (1), and a gap is formed between the lower end of the other electrode and the lower wall of the external conductor (1).

Abstract: A tunable microwave resonator, including walls delimiting a cavity, the walls including a first wall formed with an opening; a tuning screw extending in the opening, a cylindrical dielectric resonator disposed in the cavity, and a dielectric support projecting in the opening, the dielectric support acting as a spacer and rigidly connecting the dielectric resonator to the tuning screw. The cavity and the dielectric resonator are excitable in one or more resonant modes of an electromagnetic field, wherein a current induced by the resonant modes is transferred outside the cavity; and a toroidal extension formed on the first wall inside the cavity and surrounding the opening, the toroidal extension extending a given length inside the cavity, the toroidal extension reducing a thermal effect on the resonance frequency, and increasing mechanical stability.

Abstract: The invention relates to a radio frequency filter comprising at least two helix resonators (HX1-HX2) placed at a distance from each other, each of which is wound of a metal wire into a cylindrical coil. A conductor (MLIN2), preferably a microstrip line, runs between two neighboring resonators and is provided at a distance (d1, d2) from each of the resonator coils so that one part (3) of it is electromagnetically connected to one resonator (HX 1) and the other part (4) is electromagnetically connected to another resonator (HX2).

Abstract: A temperature-compensated combiner including a control rod disposed in a combiner housing for controlling a middle frequency; a resonator tube secured to the housing and coaxially disposed around the control rod; a regulating cup arranged at an end of the control rod which faces the housing; a motor which controls the middle frequency and which is arranged at one end of the control rod; and a temperature-compensating tube for compensating for longitudinal changes exhibited by a unit including the control rod, the resonator tube and the regulating cup for changes in temperature. The temperature-compensating tube is positioned within the resonator tube and secured to that end of the resonator tube which faces the housing and to the frame of the motor.

Abstract: An end face reflection type surface wave resonator utilizing a surface wave of an SH type is constructed by forming comb electrodes on one major surface of a piezoelectric substrate, which constitute an IDT, and forming grooves extending from one major surface to the other major surface to form a pair of end faces on which a surface wave is to be reflected the resonator having piezoelectric plate portions outside the grooves.

Abstract: A first interdigitated transducer and a second interdigitated transducer are disposed such that an acoustic port of the first interdigitated transducer confronts an acoustic port of the second interdigitated transducer. A first electric terminal of respective interdigitated transducers are electrically coupled together. The first and second interdigitated transducers have different resonance frequencies and may be acoustically coupled.

Abstract: A magnetic structure for a ferrite-based electromagnetic resonator comprises a toroidal permanent magnet which surrounds high permeability material forming a gap in which there is for example a YIG sphere which is tunably resonant in a magnetic field. The high permeability material also forms part of a magnetic circuit. A main electromagnetic coil, preferably a solenoid, surrounds the permanent magnetic structure and the high permeability material, and a modulation coil, also preferably in the form of a toroid, also surrounds the gap in the magnetic circuit.

Abstract: To obtain a surface acoustic wave device which can be produced with ease at a low cost and can be reduced in size without causing deterioration of characteristics, a surface acoustic wave device having input and output transducers arranged alternately on the surface of a substrate for propagating a surface acoustic wave includes metal patterns provided outside the transducers along the extension line of the propagation path of the surface acoustic wave and having at least one surface inclined at an angle .theta. (5.degree.<.theta.<85.degree. or -85.degree.<.theta.<-5.degree.) with respect to the propagation direction of the surface acoustic wave.

Abstract: A low-pass filter is obtained by inserting a third dielectric substrate having a shielding electrode on its upper surface between a first dielectric substrate having microstriplines on its upper surface and a second dielectric substrate having capacitor electrodes on its upper surface, stacking fourth and fifth dielectric substrates having ground electrodes on upper surfaces thereof on both sides of the first to third dielectric substrates, and stacking a dielectric sheet on the uppermost portion.

Abstract: 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<(N1+N3)<3.times.N2, and 2/k.sup.2 .gtoreq.(N1+N2+N3).gtoreq.0.8/k.sup.2.

Abstract: A surface acoustic wave filter device suitable for CDMA communication system includes a piezoelectric substrate, and a unidirectional input side transducer and a bidirectional output side transducer are formed on the substrate. The filter device has satisfactory filtering characteristics in terms of insertion loss, frequency characteristics, T.T.E. attenuation level, group delay time, etc.

Abstract: A surface acoustic wave filter according to the present invention is constructed by connecting in series one or two or more filter functional units each comprising a first surface acoustic wave resonator having input and output terminals connected in series with a signal line and a second surface acoustic wave resonator having input and output terminals one of which is connected to the signal line and the other of which is grounded. The first surface acoustic wave resonator is constituted by one interdigital transducer and a pair of electrically open strip type grating reflectors with the interdigital transducer interposed therebetween, and the second surface acoustic wave resonator is constituted by one interdigital transducer and a pair of electrically short strip type grating reflectors with the interdigital transducer interposed therebetween.

Abstract: A display panel is formed using a single crystal thin-film material that may be transferred to substrates for display fabrication. Pixel arrays form light valves or switches that can be fabricated with control electronics in the thin-film material prior to transfer. The resulting circuit panel is then incorporated into a display panel with a light emitting or liquid crystal material to provide the desired display.

Abstract: A filter operating with acoustical surface waves includes two acoustical paths each having one unidirectional input transducer, one unidirectional output transducer, and a reflector structure disposed between the input and output transducers. The input transducers in the acoustical paths are structurally identical, the output transducers in the acoustical paths are structurally identical, and the input and output transducers in each of the acoustical paths are spaced apart by the same distance. One of the input transducers or the output transducers are electrically connected in phase opposition, and the other of the input transducers or the output transducers are electrically connected in phase. The reflector structures in the two acoustical paths have substantially the same reflection performance, the reflector structure in one of the acoustical paths is shorter than the reflector structure in the other of the acoustical paths by .lambda.

Abstract: In a laminated dielectric resonator, twomo strip line is formed and resonant frequency is lowered. Accordingly, the length of the resonator is reduced, and the length of the strip line becomes shorter than one fourth of the wavelength with the lowered resonant frequency, which leads to further reduction of the length of the resonator. By lowering the resonant frequency, dielectric material with less relative permittivity can be used, with a result of resonator with high unloaded Q and excellent temperature characteristic. Further, at least one coupling electrode is formed as external or internal electrode to compose a capacitor together with a second strip line, and a laminated dielectric resonator is connected to an external circuit via the coupling electrode. A dielectric filter such as band pass filter, band elimination filter is so composed that the dielectric resonators are cascade-connected to one another.

Abstract: A full duplex radio (10) having improved properties obtained by using surface acoustic wave (SAW) filters (92, 100, 100') having asymmetric frequency responses (76', 76", 140). The filters (92, 100, 100') are composed of series (50.sub.1, 50.sub.1 ') and parallel (50.sub.2, 50.sub.2 ') coupled SAW resonators. Asymmetry is obtained by altering the metallization thickness of either of the series (50.sub.1, 50.sub.1 ') or parallel (50.sub.2, 50.sub.2 ') resonators of each filter (92, 100, 100') to increase or decrease the SAW coupling coefficient of some of the resonators (50.sub.1, 50.sub.1 ', 50.sub.2, 50.sub.2 ') relative to the remainder of the resonators (50.sub.1, 50.sub.1 ', 50.sub.2, 50.sub.2 '). The filters (92, 100, 100') are desirably in pairs arranged with mirror image frequency asymmetry such that the steeper skirts (93, 95) of the frequency responses (76', 76", 140) are adjacent. Greater passband bandwidths (91', 91") can be obtained without adverse affect on transmitter and receiver isolation.

Abstract: A SAW filter having an even number of tracks, each track comprising reflective input and output IDTs having a partially reflecting grating disposed between them. One of the IDTs of each pair of tracks has its electrodes connected in opposite polarity to those of the other IDTs of the pair of tracks and the separation of the input and output IDTs of respective tracks of each pair of tracks is substantially the same. The relative dispositions of the partially reflecting gratings are such that waves launched into respective tracks of a pair of tracks undergo at least one reflection from the partially reflecting grating prior to being coherently incident on the output IDTs. By virtue of the oppositely connected electrodes of one of the IDTs, direct coupling through the tracks is inhibited at substantially all frequencies.

Abstract: A resonant acoustic isolator supports a thin film acoustic resonator comprising a layer of piezoelectric material having top and bottom electrical contacts. The resonant acoustic isolator comprises at least one pair of layers of materials having different acoustic impedances. The isolator materials are deposited in alternating layers of high and low impedance material, with each layer having a thickness of 1/4 acoustic wavelength at resonant frequency. Silicon dioxide (SiO.sub.2) is preferred for the low impedance material because it is ubiquitous in the semiconductor industry, it has relatively low acoustic impedance with very low intrinsic acoustic loss, and it can be deposited using a variety of convenient methods. Hafnium oxide (HfO.sub.2) is preferred for the high acoustic impedance material because it can be deposited by evaporation to form a hard, dense dielectric having a relatively high acoustic impedance. Deposition of an entire stack of alternating SiO.sub.2 and HfO.sub.