Abstract: A dielectric filter includes a first dielectric block having a through bore extending between first and second end faces thereof and a plurality of side surfaces extending between those end faces. Substantially all of the surface area of the end faces, the side surfaces and the bore are covered with a conductive film to define a first dielectric resonator whose magnetic energy varies in the direction of an axis of the through bore. A first coupling window is formed in the conductive film on a first one of the side surfaces of the first dielectric block for coupling an input signal applied thereto to the first dielectric resonator. A second coupling window is formed on a second one of the side surface of the first dielectric block in a location wherein the magnetic energy in the first dielectric block is at a relatively high level so that magnetic energy in the first dielectric block exits the first dielectric block via the second coupling window.

Abstract: A dielectric resonator apparatus comprising at least three quarter-wavelength dielectric coaxial resonators in a dielectric block is provided. In the dielectric resonator apparatus, an outer conductor is formed on the surfaces of the dielectric block, and a pair of input and output electrodes for capacitively coupling with the two dielectric coaxial resonators located at both ends is formed close to a first end surface of the dielectric block on a predetermined side surface of the dielectric block so as to be electrically insulated from the outer conductor.

Abstract: A dielectric block having an external conductor on the outer surface and a plurality of holes with internal conductors formed therein; no internal conductors are provided near one end of each of the plurality of holes. Portions of the dielectric block and the external conductor are removed so as to obtain a dielectric resonator having desired resonator characteristics. In another embodiment, portions of the dielectric block are removed so as to bring the external conductor closer to the internal conductors thereby obtaining a dielectric resonator resonant with a desired frequency. The dielectric resonators limit leakage of electromagnetic field and do not require additional parts such as terminals and case.

Abstract: A dielectric filter which includes a dielectric block having a plurality of through-holes defined therein so as to extend parallel to each other and spaced a predetermined distance from each other. Each of the through-holes has a peripheral wall lined with an electroconductive material to provide a respective hole electrode. This hole electrode has an isolation region dividing such hole electrode into two separate electrode components. The dielectric filter also has at least one terminal member provided within one of the through-holes and coupled through a dielectric element separate from the dielectric block.

Abstract: A compact dielectric resonator apparatus is comprised of a dielectric block having a plurality of mutually parallel throughholes formed therethrough with inner surfaces covered with a conductive film so as to provide coaxial resonators. The degree of coupling between a mutually adjacent pair of such dielectric resonators can be adjusted by forming grooves, a bottomed hole or a slit or burying a conductive plate therebetween in the dielectric block, and varying physical characteristics of such grooves, bottomed hole, slit and/or conductive plate, without changing the separations between the throughholes or the external dimensions of the dielectric block.

Abstract: A dielectric resonator apparatus comprising a plurality of dielectric coaxial resonators has a dielectric block with first and second surfaces and a plurality of side surfaces located therebetween, and a plurality of cylindrical resonator holes are formed in parallel to each other so as to penetrate the dielectric block, each of the resonator holes having an opening at the first surface and another opening at the second surface. Further, an outer conductor is formed on the first and second surfaces and a plurality of side surfaces, and a plurality of inner conductors is formed on the plurality of resonator holes, respectively.

Abstract: Coupling capacitors are connected between an input end and an output end, a resonator is connected between each of the coupling capacitor and the ground, and a capacitor and a switch are connected between one end of each resonator and the ground. When the capacitor is off, the frequency is set to the resonance frequency of the resonator, and when the switch is turned on, the capacitor is connected parallel to the resonator, so that the resonance frequency is shifted to a lower value, whereby a dielectric filter having multiple frequencies can be obtained.

Abstract: A band-pass filter which includes a plurality of dielectric coaxial resonators which are arranged in a parallel relation and extending axially in the same direction, and have respective coupling terminals inserted therein, and a dielectric substrate formed, on its first surface, with a plurality of coupling electrodes for connecting the respective coupling terminals. The coupling electrodes on the first surface of the dielectric substrate have an inductance element between them for connecting at least two coupling electrodes to each other. Confronting electrodes facing the coupling electrodes are formed on the other surface of the dielectric substrate to from a capacitance bypass circuit. The inductance element may be a printed circuit on the dielectric substrate or an air-core coil. The air-core coil may be located either adjacent the first surface of the substrate, or away from the substrate between the resonators.

Abstract: A dielectric filter having band elimination characteristics includes a resonance circuit with a coupling terminal. A proximal portion of the coupling terminal and a ground electric potential portion of the filter are opposed in the vertical direction, and a stray capacitance element and an external coupling element are provided in the vertical direction between them. Thus it is possible to effect the mounting operation by first stacking the stray capacitance element and the external coupling element on the ground portion and on top of those securing the proximal portion of the coupling terminal. This structure simplifies the soldering and assembling operation, and also improves mass production.

Abstract: A dielectric filter which includes a plurality of dielectric resonators, and a plurality of coupling capacitors connected in series to each other, at least one portion of respective portions between the neighboring coupling capacitors being grounded through a series circuit of a series resonance capacitor and the corresponding one of the dielectric resonators, and other portions of the respective portions between them being grounded through other dielectric resonators. The coupling capacitors are each formed between electrodes formed on a substrate, and the series resonance capacitor is formed to confront the electrodes constituting the coupling capacitors.

Abstract: A filter having an improved frequency adjustment construction which is capable of conforming the frequencies of the resonators with better accuracy through improvements in the accuracy of the sizes of the electrodes used for frequency adjustment, and through better stabilizng of the filter characteristics through forming a positive connection between each electrode for adjustment use and the corresponding inner conductive film. Electrodes for adjustment use are formed on a base plate, which is a separate unit from the dielectric block, so as to connect them with the respective resonators through coupling members, whereby the size accuracy of the electrodes for adjustment use is improved so as to considerably improve the frequency adjustment accuracy. Also, the connection between the electrodes for adjustment use and the inner conductive films of the respective resonators is positively stabilized to improve the stability of the filter characteristics.

Abstract: A dielectric filter includes a plurality of coaxial resonators constituted by inner conductors formed on inner walls of a plurality of throughholes which are formed in parallel with each other on a dielectric block and an outer conductor which is formed on an outer surface of the dielectric block. A printed circuit board is disposed at a side of an open end of the dielectric block, and the printed circuit board and the dielectric block are accommodated in a metallic case which is electrically connected to the outer conductor. A projecting portion is formed on an inner surface of the metallic case to support the printed circuit board such that a predetermined gap can be formed between the printed circuit board and a bottom surface of the metallic case by the projecting portion, whereby a stray capacity is reduced. Therefore, it is possible to prevent resonant frequencies of the coaxial resonators from being changed or fluctuated, and thus a filter characteristic of the dielectric filter becomes good.

Abstract: A dielectric filter includes a single block made of dielectric material having three or more through holes, in each of which an inner conductor is deposited, to define three or more dielectric resonators coupled in a cascade manner. Coupling holes are each formed between a pair of neighboring dielectric resonators. A bypass circuit, having a reactance component, is provided for connecting between two or more coupling holes; or for connecting the through hole of the dielectric resonator and a coupling hole; or for connecting the input terminal and one or more through holes of the dielectric resonators or the coupling holes. By selecting the holes to be interconnected and the value of the reactance of the bypass circuit, it is possible to provide a filter having a frequency characteristic in a desired format, including at least one pole at a selected point in an attenuation region thereof, without any increase in the number of dielectric resonator stages of the dielectric filter.

Abstract: An assembly which comprises a plurality of dielectric coaxial resonators, each comprising a generally elongated, polygonally-sectioned dielectric body having a hollow coaxially defined therein so as to extend completely through the length of the dielectric body, and also having inner and outer conductors formed respectively on inner and outer peripheral surfaces thereof, and a mount for the support thereon of the coaxial resonators. The mount has side abutments set up from the mount for engagement with respective sides of the coaxial resonators whereby the position of each coaxial resonator relative to the mount can be restricted by the corresponding side abutments.

Abstract: A dielectric filter for use in a microwave integrated circuit includes a substrate made of ceramics and a plurality of dielectric resonators mounted on the substrate. The substrate has a ground electrode, input and output strip lines, and a plurality of capacitance electrodes. The dielectric resonator has a body made of a dielectric material with a through hole formed therein, an inner electrode deposited on the wall defining the through hole, and an outer electrode deposited on an outer surface of the body. The inner electrode is electrically connected to the capacitance electrode, and the outer electrode is electrically connected to the ground electrode.

Abstract: An improved electrical filter device which is so arranged that a low-pass filter having a spurious wave eliminating function is formed into a compact size so as to be incorporated into a dead space within the filter device, while at the same time, high frequency characteristics of said low-pass filter itself are improved, without deteriorating characteristics of the filter device in which the low-pass filter is to be incorporated.

Abstract: An improved electrical trap construction for use in a high frequency circuit device, which is so arranged that a coaxial resonator is connected to a core pin of a coaxial connector mounted on a case which contains the device, so that main currents received from a hot signal line flow into or flow out of the coaxial resonator the inner conductive electrode layer of the coaxial resonator is in electrically conducting contact with the core pin of the connector so as to allow the coaxial resonator to provide parallel resonance at a frequency to be trapped.

Abstract: An improved distribution constant type filter provided with a connecting arrangement which includes a through-opening formed in a dielectric block of the filter along a first cavity of a resonance unit at an initial stage, and a connector provided in the through-opening so that one end of the connector is electrically conducted to a conductive layer formed on part of the outer surface of the dielectric block, with the other end of the connector being connected to an external circuit to receive an input signal. The through-opening is preferably small in lateral cross section relative to the first cavity and positioned at a central portion in a widthwise direction of the dielectric block, and thus, coupling magnetic between the resonance unit and the external circuit suppresses a TE11 resonance mode in the filter.

Abstract: An improved electrical filter device in which cut-off spaces required in a casing of the electrical filter device are still further reduced than in conventional arrangements, and which is free from unnecessary coupling and capable of being constructed entirely by capacitor coupling for compact size.