Abstract: A band reflection type oscillator includes a GaAs-FET having a source, a gate and a drain in which the drain is connected to ground. A stripline is connected to the gate, and a dielectric resonator is provided adjacent the stripline in a magnetically coupled relationship therewith. A stripline stub is electrically connected to the drain and positioned adjacent the resonator in a magnetically coupled relationship therewith, thereby defining a positive feedback circuit through the drain, said stripline stub, the resonator and the stripline to the gate. By the positive feedback circuit, the oscillation stability is improved.

Abstract: An oscillation circuit comprises a resonator and frequency switching means for switching oscillating frequencies of the resonator, said frequency switching means including a capacitor and an electrical switching element in series, said electrical switching element having a small capacitance as compared to that of said capacitor and a conductive voltage larger than a peak voltage of the oscillation circuit output applied across the electrical switching element. Preferably, the electrical switching element is a diode.

Abstract: An apparatus for detecting a variation of an electrostatic capacitance is advantageously utilized for reproducing information from a groove or pit formed on a disc of a CED type or a VHD type, for example, and comprises an oscillator and a resonance circuit each including a dielectric resonator, wherein the oscillator and the resonance circuit are capacitively coupled, while the resonance frequency of the resonance circuit is changed in accordance with a change of the electrostatic capacitance to be detected, whereby a signal output dependent on a variation of the electrostatic capacitance is obtained from a detector directly coupled to the resonance circuit.

Abstract: An improved distribution constant type electrical filter which is so arranged that columnar or cylindrical dielectric units each having conductive wires axially extended through it, are inserted into through openings formed in a dielectric material block and provided on their inner peripheral faces with inner electrically conductive layers for electrostatic coupling between the conductive wires and the inner electrically conductive layers.

Abstract: A dielectric resonator has a sector shape, and a filter has a signal source for emitting signal to be filtered, signal receiver for receiving the filtered signal and a path defined between the signal source and the signal receiver. At least one sector shaped dielectric resonator is disposed in the path.

Abstract: A 1/4 wave length coaxial resonator comprises an outer cylindrical portion, an inner cylindrical portion positioned coaxially in the outer cylindrical portion, with the outer and inner cylindrical portions connected at one end by a radial connecting portion, and a dielectric unit disposed therebetween. The outer cylindrical portion and the inner cylindrical portion and the radial connecting portion are formed with a unitary member of a metallic extruded material formed by means of an impact extruding process so that the inner cylindrical portion is positioned coaxially in the outer cylindrical portion. As a result, a space is formed between the outer cylindrical portion and the inner cylindrical portion to allow for insertion of a hollow cylindrical dielectric unit.

Abstract: The disclosure relates to an improved microwave device which includes a casing of electrically conductive material, at least two coaxial resonators, for example, 1/4 wavelength coaxial TEM resonators each having dielectric member disposed between an inner conductor and an outer conductor of the coaxial resonator and a terminal electrode secured in the inner conductor to provide a terminal portion projecting from an end face of each of the coaxial resonators. The resonators are accommodated in the casing so as to be electrically connected and mechanically secured to the casing. A dielectric plate member connecting input and output terminals of the device is provided at least two coupling electrodes spaced predetermined intervals from each other are provided on the dielectric plate member. The microwave device is arranged to obtain coupling electrostatic capacity mainly between the coupling electrodes provided on the main flat surface of the dielectric plate member.

Abstract: A dielectric resonator is housed within an internal space of a metallic casing. An amplifier is disposed outside the space and an input and output circuits are connected to the amplifier. An output coupling window is formed in the casing at the position corresponding to the output circuit of the amplifier and an input coupling window is formed in the casing at the position corresponding to the input circuit of the amplifier. An electromagnetic wave leaking from the output circuit of the amplifier is coupled through the output coupling window to the dielectric resonator and the dielectric resonator is further coupled to the input circuit of the amplifier through the input coupling window.

Abstract: An oscillator comprises two leakage lines extending in parallel with a dielectric resonator positioned therebetween, within a housing made of metal. The dielectric resonator is electromagnetically coupled to the respective leakage lines with a predetermined coupling degree through coupling gaps formed between the dielectric resonator and the respective leakage lines. The dielectric resonator is disposed at an optimum position for establishing an oscillating condition of the oscillator. Preferably, the dielectric resonator is movable in the length direction of the leakage lines.

Abstract: The disclosure relates to an improved coaxial resonator and an electrical filter employing such coaxial resonators. The electrical filter includes a casing of electrically conductive material, at least more than one coaxial resonators, for example, 1/4 wavelength coaxial TEM resonators each having dielectric member disposed between inner conductor and outer conductor of the coaxial resonator and a terminal electrode secured in the inner conductor to provide a terminal portion projecting from an open end face of each of the coaxial resonators, and accommodated in the casing so as to be electrically connected and mechanically secured to the casing, and coupling members for electrically coupling the resonators to each other at the terminal portions and also to input and output connectors for said electrical filter.

Abstract: A filter device has two filters for filtering or separating two high-frequency signals having different frequencies. Each filter comprises a plurality of quarterwavelength coaxial resonators, cables for connecting the filters with terminals, and a casing for accommodating the two filters. Either the respective input cables or the respective output cables of the two filters are joined in a tee joint. The casing is constituted of two cooperating blocks each having grooves to precisely accommodate the two filters and the cables. The two-part casing maintains the tee joint and obviates the need for a conventional T-shaped metallic coupling member, and makes manufacture very easy.

Abstract: An electrical filter comprising a cylindrical metal case having an aperture extending in a line, a plurality of 1/4 wave length transverse electromagnetic mode coaxial resonators inserted in the aperture of the metal case in an electrical series fashion, each resonator including a dielectric resonator comprising a cylindrical dielectric material, an outer conductor and an inner conductor, the open circuit ends of the adjacent dielectric resonators being capacitively coupled and the short circuit ends of the adjacent dielectric resonators being inductively coupled by means of a coupling electrode having a coupling window. Preferably, a portion of the dielectric material having a lesser influence upon the fundamental mode is made in a lower dielectric constant to improve the spurious response characteristic.

Abstract: A T-shaped rectangular waveguide branching filter includes an electrically conductive projection or protrusion of approximately triangular cross section which is formed at a predetermined portion within the branching filter for preliminary impedance matching of a predetermined accuracy as observed from each of the input/output ports of the branching filter, and an electrically conductive rod which may be selectively advanced toward or retracted from the first input/output port and extends through the electrically conductive protrusion of triangular cross section so that, by selectively advancing or retracting the conductive rod, a particular impedance match corresponding to each of the input/output ports as observed from any one of the input/output ports may be achieved for efficiently deriving the signal applied to one of the input/output ports from either one of the other input/output ports.

Abstract: A band rejection coaxial filter for use with a coaxial transmission line, for example, comprises a casing made of a conductive material and having an internal geometry selected to be in a cut off state with respect to the frequency of a signal being transmitted along the coaxial transmission line. The casing is coupled to the coaxial transmission line and a leakage coaxial cable is provided in the casing, so as to be coupled to the coaxial transmission line through the casing. The leakage coaxial cable is formed of a plurality of leakage openings spaced apart from each other a quarter wave length of the resonance frequency of the resonators in the axial direction for allowing for leakage of the transmission signal. A corresponding plurality of dielectric resonators are provided spaced apart a given distance from and faced to the leakage openings, so that a portion of the transmission signal of the frequency determined by the dielectric resonators is trapped.

Abstract: An interdigital filter comprising a plurality of resonators each comprising a resonant conductor rod coupled to each other in the even and odd modes of a transverse electromagnetic wave, wherein each resonant conductor rod is enclosed with a dielectric material so as to increase the ratio of the odd mode characteristic impedance to the even mode characteristic impedance.

Abstract: The present invention is an electrical filter which includes coaxial resonators, for example, both-end open type 1/2 wave length TEM (transverse electro-magnetic mode) coaxial resonators, each having dielectric material, for example of titanium oxide group, filling the space between an inner conductor and an outer conductor of the resonator for reduction of size and weight of the resonator with optimum quality factor Q and temperature characteristics, while the predetermined number of these coaxial resonators are accommodated in one or more than two bores longitudinally formed in parallel relation to each other in a filter casing of conductive material for coupling the resonators to each other through capacitors.

Abstract: A microwave band-pass filter has a casing, at least one dielectric resonator in the casing and at least one metallic adjusting screw supported by a wall of the casing and positioned adjacent the dielectric resonator with the tip end of the screw closely adjacent the resonator, so as to improve the sensitivity characteristics of the filter especially in the region higher than the resonance frequency.

Abstract: A dielectric resonator is made up of a block of dielectric material and a synthetic resin bonded onto the dielectric material for precisely adjusting the required resonance frequency of the resonator. The resonance frequency is reduced by an increase of the amount of synthetic resin and the resonance frequency is increased by a decrease of the mass of synthetic resin.

Abstract: The present disclosure relates to a dielectric resonator for use in microwave filters and other devices for receiving microwave. The arrangement of the present disclosure comprises a resonator made of a dielectric material of any known type and a bar member provided approximately in alignment with the direction of formation of the electric field produced by the propagation of a spurious mode in the dielectric resonator. During the propagation of the dominant mode accompanied by the spurious mode, the electric field produced by the spurious mode causes the bar member to produce a current flowing therethrough, thus consuming the energy of the spurious mode in the bar member, and substantially eliminating the spurious mode.

Abstract: A dielectric resonator unit for use in electrical filters which includes a dielectric resonator made of ceramic material and a supporting spacer made of other types of ceramic material or synthetic resin. The supporting spacer is formed in the shape of a cylinder and has one end thereof bonded onto the dielectric resonator and the other end thereof bonded onto an inner surface of the casing of the filter. The combination of a particular dielectric resonator with a particular supporting spacer is determined by the value of temperature-frequency characteristics and temperature dielectric constant characteristics of the respective resonator and spacer, so that the resulting dielectric resonator unit has values of substantially Oppm/.degree. C for both characteristics.