Abstract: A delay filter uses the dielectric mono-block triple-mode resonator and unique inter-resonator coupling structure, having smaller volume and higher power handling capacity. The triple-mode mono-block resonator has three resonators in one block. An input/output probe is connected to each metal plated dielectric block to transmit microwave signals. Corner cuts couple a mode oriented in one direction to a mode oriented in a second, mutually orthogonal direction. An aperture between two blocks couples all six resonant modes, and generates two inductive couplings by magnetic fields between two modes, and one capacitive coupling by electric fields. The input/output probes, coupling corner cuts and aperture are aligned such that all six resonators are coupled in the desired value and sign, so constant delay on the transmitted signal within certain bandwidth can be achieved. By connecting the input and output probes to the base printed circuit board, the delay filter is surface mountable.

Abstract: A multi-layer dielectric resonant device has a dielectric resonator and a microstrip line to be coupled to the dielectric resonator. The dielectric resonator includes a first dielectric layer, a second dielectric layer, a third dielectric layer, a metallic substrate and a metallic plate. The second dielectric layer is placed on the first dielectric layer and has a dielectric constant higher than that of the first dielectric layer. The third dielectric layer is placed on the second dielectric layer and has a dielectric constant lower than that of the second dielectric layer. The metallic substrate is placed in the center portion of the second dielectric constant layer to reduce the conductor loss of the dielectric resonator. The metallic plate constitutes the outer wall of the dielectric resonator.

Abstract: A small in-band-flat-group-delay type dielectric filter having low-loss characteristics with a small amplitude deviation and uniform-group-delay frequency characteristics is obtained, which enables broad-band characteristics to be obtained easily. The in-band-flat-group-delay type dielectric filter includes a plurality of dielectric coaxial resonators, a coupling circuit comprising a combination of reactive elements, with which the dielectric coaxial resonators are coupled to one another, and input/output terminals connected to ends of the coupling circuit. The dielectric coaxial resonators coupled to the input/output terminals are allowed to have a different characteristic impedance from that of the inter-stage dielectric coaxial resonators.

Abstract: A continuously variable waveguide attenuator (100). The continuously variable waveguide attenuator includes at least one waveguide attenuator cavity (109) having at least one barrier. A fluid dielectric (108) having a loss tangent, a permittivity and a permeability is at least partially disposed within the waveguide attenuator cavity (109). At least one composition processor (101 ) is included and adapted for dynamically changing a composition of the fluid dielectric (108) to vary an electrical characteristic of the fluid dielectric. A controller (136) is provided for controlling the composition processor (101 ) to selectively vary the electrical characteristic in response to a waveguide attenuator control signal (137).

Abstract: A new type of dielectric resonator loaded metal cavity filters that are compact and resonate only the desired frequency, along with a method of making such filters. The more compact dielectric resonator loaded metal cavity filter is made by a method of stacking resonator loaded cavities into a filter. A method of making a dielectric resonator filter or duplexer filter which inhibits the undesired higher order harmonics from passing through the filter. Whereby, the method for inhibiting higher order harmonics includes differentiating sizes of the dielectric resonator and metal cavity as compare to other cavities in the filter to prevent the passage of undesired higher order harmonics through the filter.

Abstract: A dielectric resonator device includes two dielectric resonators resonating in first and second resonant modes and a partitioning plate which partitions the two dielectric resonators. Slits S are provided in the partitioning plate. A magnetic loop of the first resonant mode (TE01?z mode) is directed along the length of the slits S. The partitioning plate is also provided with a conductor loop consisting of first and second conductor loop portions that are coupled to magnetic fields of the second resonant mode (TE01?y mode). Accordingly, the coupling of the second resonant mode between the two dielectric resonators can be suppressed by the coupling of a leakage of the magnetic fields passing through the slits S and the coupling of the magnetic fields by the provision of the conductor loop.

Abstract: A high-frequency circuit device includes a dielectric member 1, a shielding conductor 2 surrounding the dielectric member 1, a support member 3 for fixing and supporting the dielectric member 1, and a pair of transmission lines 4 each of which is formed of a microstrip-line. Each of the transmission lines includes a substrate 6 formed of a dielectric material, a strip conductor 5, and an earth conductor layer 9. An end portion of the strip conductor 5 faces part of the dielectric member 1 and functions as a coupling probe for input/output coupling. Each of the transmission lines 4 is formed of a strip line, a mictostrip line, a coplanar line or the like, and has low-loss when connected to a circuit board.

Abstract: The dielectric loaded cavity for high frequency filters consists of a metal container housing s dielectric block held in position by supporting plates, that also sustains coupling and tuning elements. This invention provides broadband filters, small in size and with low losses. Its high symmetry structure considerably reduces the energizing of spurious modes and furthermore facilitates the design using automatic calculation procedures, on the basis of accurate electromagnetic models.

Abstract: A dielectric resonator device includes a dielectric substrate. Electrode films are formed on the front and back surfaces of the dielectric substrate, respectively. A TE010-mode resonator is constituted by two circular openings which oppose each other and which are formed in the electrode films. Two opposing slots formed in the electrode films constitute a planar dielectric transmission line (PDTL). The PDTL is connected to the TE010-mode resonator. An excitation section is formed by extending two portions of each electrode film on two side of each slot into each opening.

Abstract: A high frequency dielectric ceramic composition includes: as a major component a composition which contains a rare earth element (Re), Al, Sr, and Ti as metal elements and has a composition formula expressed by a molar ratio of aRe2O3-bAl2O3-cSrO-dTiO2 in which a, b, c, and d satisfy the following formula; 0.113?a?0.172, 0.111?b?0.171, 0.322?c?0.388, 0.323?d?0.396, and a+b+c+d=1.000; and 0.01 to 2 parts by weight on a Fe2O3 conversion basis of Fe as an element, based on 100 parts by weight of the major component.

Abstract: A high-frequency circuit device serving as a resonator includes a substrate and an electrode film which is formed on the surface of the substrate and which includes a conductive film and a dielectric film. The conductive film is formed around the substrate such that both ends of the conductive film overlap each other when viewed in a predetermined cross-section of the substrate, and the dielectric film is inserted between both ends of the conductive film. Accordingly, a self-capacitance portion is formed at the overlapped portion of the conductive film, electric-field energy is accumulated therein, and magnetic-field energy is accumulated inside the substrate. With this step impedance structure, the entire high-frequency circuit device can be miniaturized.

Abstract: The resonator of the present invention includes a cylindrical dielectric and a conductor film covering the surface of the dielectric in close contact therewith. The conductor film is constructed of a cylindrical portion and two flat portions, and is formed by subjecting the surface of the dielectric to metallization or the like. With the conductor film formed in close contact with the dielectric, deterioration of the Q value and the like caused by instability of connection at the corners can be suppressed even when a radio frequency induced current flows from the cylindrical portion over the two flat portions.

Abstract: A dielectric filter includes a dielectric block having a plurality of through holes; an outer conductor provided on an outer surface of the dielectric block; and inner conductors provided on inner surfaces of the plurality of through holes. The dielectric filter also includes a first dielectric provided between the respective inner conductors and the outer conductor; and at least one second dielectric provided between the inner conductors of two adjacent through holes. The temperature coefficient of the resonant frequency of the first dielectric is different from that of the second dielectric. If inductive coupling between the adjacent resonators generates an attenuation pole at a frequency higher than a pass band, the temperature coefficient of the resonant frequency of the first dielectrics is set to a predetermined positive value, and the temperature coefficient of the resonant frequency of the second dielectric is set to a predetermined negative value.

Abstract: An excitation hole is provided inside a dielectric block and, on the outer surface of the dielectric block, an input-output terminal electrically connected to an inner conductor inside the excitation hole is formed at one end portion of the excitation hole. A grounding-electrode-free portion is provided on the surface opposite to an input-output electrode of a mounting substrate with which the input-output terminal makes contact. Thus, the electric field strengths in upward and downward directions toward an outer conductor of the dielectric block from the excitation hole are balanced to suppress spurious TE-mode signals, etc.

Abstract: The present invention provides a dielectric resonator having increased reliability with respect to thermal cycle fatigue of a joint between a conductive cavity and a dielectric core disposed in the cavity without an increase in material cost and processing cost, a filter and duplexer each using the dielectric resonator, and a communication device including these devices. The dielectric resonator has a structure in which the dielectric core is provided in the cavity through earth plates. Each of the earth plates has slits provided at positions in contact with the four corners of each of two opposing side faces of the dielectric core. Of the four sides of each of the earth plates, the two sides provided with spring portions are preferably inclined so that the distance between the two sides decreases toward the bottom of the cavity, and concave portions are formed in the inner surface of the cavity corresponding to the two inclined sides.

Abstract: A ceramic material suitable for use as a microwave band filter for telecommunications equipment comprises oxides of titanium, barium, neodymium, samarium, and optionally, bismuth, and containing, on an elemental weight basis: about 28 to about 31 weight % titanium, about 19 to about 21 weight % barium, about 11 to about 18 weight % samarium, about 7 to about 13 weight % neodymium, up to about 3 weight % of bismuth, and the remainder substantially being oxygen. The ceramic compositions have a resonant frequency, f, in the range of about 2000 MHz to about 2300 MHz, a quality factor, Q, of at least about 4000, a dielectric constant, K, in the range of about 50 to about 70, and a temperature coefficient of resonant frequency, Tf, in the range of about 0 ppm to about +20 ppm. Calcined metal oxide powders useful for preparing the microwave ceramic materials, a method of making the ceramic materials, and devices containing the ceramic materials are also described.

Abstract: A small dielectric duplexer using a small TM mode dielectric resonator having a low loss is formed. On the transmission side thereof, TM double mode dielectric resonators and a TM triple mode dielectric resonator are arranged in a line so that their opening surfaces face the same direction. On the receiving side thereof, TM single mode dielectric resonators and a TM triple mode dielectric resonator are also arranged in the same direction in a similar manner as the transmission side. The external dimensions of the plurality of these dielectric resonators are made uniform by selecting a dielectric having a dielectric constant according to the degree of multiplexing. The opening surfaces of the cavities are covered by a panel having input/output terminals, an antenna connection terminal and input/output loops and by a panel having coupling loops. In this manner, a small dielectric duplexer with uniform external dimensions and a low loss is formed.

Abstract: A high-frequency circuit device includes a dielectric substrate. A planar conductor is provided on each of top and bottom surfaces of the dielectric substrate and a slot line is formed on the top surface. Also, undesired-wave propagation preventing circuits, each including multistage band-elimination filters, are provided on the top surface of the dielectric substrate, with the slot line therebetween. Each of the band-elimination filters includes two conductive lines and a resonator which is provided at a portion of one of the conductive lines and which includes two spiral lines. Accordingly, propagation of an undesired wave of the band whose center is the resonance frequency of the resonator can be prevented.

Abstract: A multi-layer microwave resonator (10) comprises a cavity (12) having an inner surface formed from an electrically conductive material. Pieces (16a-16e) of dielectric materials stacked on top of each other form a conriguous body (14) that is provided in the cavity (12). The dielectric materials of the pieces (16a-16e) are chosen such that the dielectric constant of the pieces (16a-16e) alternate between a relatively high dielectric constant and a relatively low dielectric constant.

Abstract: A high frequency oscillator includes a dielectric, cylindrical resonator (DR) as a frequency-determining element. The dielectric resonator (DR) is arranged vertically on a substrate (S) on its shell. The resonator (DR) is formed as a hoop, such that the field intensity in the region of the outer edge of the hoop is at a maximum and in the center, is null, that is field-free.

Abstract: A tunable resonant system (100) and a method for a varying the resonant characteristics of a resonant cavity (102). The resonant cavity (102) is enclosed by a conductive material that has at least one aperture (104) for coupling the resonant cavity (102) to an RF signal propagating in a circuit device (160). A fluidic dielectric (108) having at least one among a permittivity, a permeability and a loss tangent is at least partially disposed within the resonant cavity (102). A dielectric barrier (105) can be provided within the aperture to prevent fluid (108) from escaping the resonant cavity. A composition processor (101) is adapted for dynamically changing a composition or volume of the fluidic dielectric to vary at least one among the permittivity, the permeability and/or the loss tangent to vary, or maintain constant, a center frequency, a bandwidth, a quality factor (Q) or an impedance of the resonant cavity (102).

Abstract: A microwave cavity has a cut resonator therein that is conductor-loaded. Filters made from one or more cavities having cut resonators therein have improved spurious performance over previous filters. A filter can have two conductor loaded resonators in one cavity or a combination of conductor loaded resonators and dielectric resonators in different cavities.

Abstract: The present invention provides a dielectric duplexer 10 comprising a receiving filter 1 and a transmitting filter 2 which are connected in parallel with an antenna connecting terminal portion 17, and both the filters 1, 2 are integrally assembled into a common dielectric block 11. A trap circuit 8 for suppressing a predetermined frequency band different from the receiving band of the receiving filter 1 and from the transmission band of the transmitting filter 2 is integrally assembled into the dielectric block 11 along with the filters 1, 2, and is connected to the antenna connecting terminal portion 17.

Abstract: A high-frequency dielectric ceramic member is composed of an oxide ceramic containing Mg, Ba, Re, Ti, and O, wherein Re is at least one element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Dy, and Er. The oxide ceramic is represented by the formula aMgO-bBaO-cRe2On-(100-a-b-c)TiO2, wherein n=3 when Re is La, Nd, Sm, Eu, Dy, or Er, n=11/3 when Re is Pr, and n=4 when Re is Ce, wherein a, b, and c, in mole percent, satisfy the relationships 10.0?a?62.0, 0<b?14.0, and 0<c?16.5. A dielectric resonator, a dielectric filter, a dielectric duplexer, and a communication device, each including the high-frequency dielectric ceramic member, are also disclosed.

Abstract: An oscillation apparatus has a multi-mode dielectric resonant element; a plurality of oscillation circuits, each including a line coupled to the dielectric resonant element and active devices connected to ends of the line; and a substrate having the lines and the active devices provided thereon. The dielectric resonant element is placed on the substrate. The magnetic fields, occurring in the dielectric resonant element, in a plurality of resonant modes having different resonant frequencies are coupled to the corresponding lines in the plurality of oscillation circuits.

Abstract: A cavity filter which provides for fine tuning of the bandwidth of the filter. The filter provides for both capacitive cross-coupling and inductive coupling between physically adjacent but electrically non-adjacent resonators in the filter. The isolation of the filter can be fine tuned by adjusting the inductive coupling between these resonators, which has the effect of attenuating the cross-coupling effect between these resonators.

Abstract: A dielectric ceramic composition containing a first component and a second component (25 to 80 wt %) is used. The first component is a complex oxide represented by Formula: xZrO2-yTiO2-zL(1+u)/3M(2−u)/3O2 (L is at least one element selected from the group consisting of Mg, Zn, Co, and Mn, and M is at least one element selected from the group consisting of Nb and Tb. x, y, z, and u are numerical values represented by x+y+z=1, 0.10≦x≦0.60, 0.20 ≦y≦0.60, 0.01≦z≦0.70, 0≦u≦1.90). The second component is a glass composition containing an oxide of at least one element selected from the group consisting of Si, B, Al, Ba, Ca, Sr, Zn, Ti, La, and Nd.

Abstract: The invention is a method and apparatus for dissipating heat in a dielectric resonator circuit in which resonators are mounted to an enclosure by highly thermally and electrically conductive supports, such as metal rods, that pass through the longitudinal through hole in the center of the resonator. The supports preferably are attached within the through holes by a highly thermally conductive, but dielectric sleeve positioned between the support and the resonator. The rod or support has a diameter selected to minimize any reduction in quality factor, Q, for the circuit. Alternately, the support can be a highly thermally conductive dielectric and the inner wall of the through hole can be metalized.

Abstract: A dielectric resonator includes a high-frequency dielectric ceramic containing a first ceramic having an adhesive strength of 70 newtons or more per 2 millimeter square to metallic coatings and a second ceramic having an adhesive strength of less than 70 newtons per 2 millimeter square to metallic coatings. The dielectric ceramic has composition in which the condition 10≦{A/(A+B)}×100<100 is satisfied, where A represents the volume of the first ceramic and B represents the volume of the second ceramic.

Abstract: In a high-frequency circuit having a substrate having a high-frequency transmission line and an dielectric resonator formed on said substrate so that said dielectric resonator and said high-frequency transmission line may be coupled electro-magnetically to each other, a hole part or a cavity part is formed at a part of said substrate and a dielectric resonator is embedded in said hole part or said cavity part. In the same object, a high-frequency circuit having a dielectric resonator is produced by the step for forming a high-frequency transmission line on a substrate, the step for forming a hole part or a cavity part on a part of the substrate, and the step for mounting a dielectric resonator in the hole par formed on the surface of the substrate.

Abstract: The dielectric resonance device according to the present invention is constructed such that there are provided a column-shaped dielectric resonator and a column-shaped pedestal bonded to the undersurface of the dielectric resonator with the adhesive, for supporting the dielectric resonator, that on the joint surface between the pedestal and the dielectric resonator, there is provided an adhesive collecting recess so as not to reach a side of the pedestal, and that the joint surface and the undersurface of the dielectric resonator are bonded to each other with the adhesive. Therefore, the recess serves as a place for collecting the adhesive so that the adhesive which is squeezed out from between the joint surface and the undersurface of the dielectric resonator can be eliminated, making it possible to provide a dielectric resonance device with stabilized electric performance.

Abstract: A high-frequency dielectric ceramic composition that has a high Q-factor as well as a large relative dielectric constant, and in which temperature coefficient of the resonant frequency (&tgr;r) can be controlled to around 0 ppm/° C. is provided. The dielectric ceramic composition has a general formula of Ba[(Sn&agr;Zr1-&agr;)xMgy(Nb&bgr;Ta1-&bgr;)z]vOw, wherein molar ratios x, y, and z are within an area defined by points A (0.30, 0.22, 0.48), B (0.60, 0.12, 0.28), C (0.60, 0.14, 0.26), and D (0.30, 0.25, 0.45) in a ternary diagram, and are not on the line between points A and D, x+y+z=1.00, 0.5≦&agr;≦1.0, 0≦&bgr;<1.0, 0.98≦v≦1.03, and w is a positive value to keep the composition electroneutral.

Abstract: A dielectric resonator having a first layer of alumina and a second layer of TiO2 is disclosed which has a superior combination of properties such as low dielectric loss, low temperature coefficient and high thermal conductivity.

Abstract: A dielectric resonator device includes two dielectric resonators resonating in first and second resonant modes and a partitioning plate which partitions the two dielectric resonators. Slits S are provided in the partitioning plate. A magnetic loop of the first resonant mode (TE01&dgr;z mode) is directed along the length of the slits S. The partitioning plate is also provided with a conductor loop consisting of first and second conductor loop portions that are coupled to magnetic fields of the second resonant mode (TE01&dgr;y mode). Accordingly, the coupling of the second resonant mode between the two dielectric resonators can be suppressed by the coupling of a leakage of the magnetic fields passing through the slits S and the coupling of the magnetic fields by the provision of the conductor loop.

Abstract: A microwave dielectric ceramic composition comprises a composition of the formula xMO-yLa2O3-zTiO2 wherein M is selected from Sr and Ca and x:y:z=1:2:4, 2:2:5, 1:2:5, 1:4:9.

Abstract: In a dielectric resonator device, the outer shape of a support base is larger than the bottom surface of a dielectric core which is in contact with the support base, and the support base is fixed on the inner bottom surface of the cavity with support columns at the periphery of the support base. With this configuration, an air space can be provided between the inner bottom surface of the cavity and the support base. Accordingly, the resonant frequency of the TMz mode in which the electric field vector directs perpendicularly to the surface of the support base is increased so that it is considerably away from the resonant frequency of the TE01&dgr; multiple mode.

Abstract: The resonator of the present invention includes a cylindrical dielectric and a conductor film covering the surface of the dielectric in close contact therewith. The conductor film is constructed of a cylindrical portion and two flat portions, and is formed by subjecting the surface of the dielectric to metallization or the like. With the conductor film formed in close contact with the dielectric, deterioration of the Q value and the like caused by instability of connection at the corners can be suppressed even when a radio frequency induced current flows from the cylindrical portion over the two flat portions.

Abstract: A dielectric resonator device comprising resonators small in size, having plural stages, and a dielectric resonator device with a high Qo, in a multimode are provided. A substantially parallelepiped-shaped dielectric core to resonate in plural modes such as TM01&dgr;-x, -y, -z, TE01&dgr;-x, -y, -z, and so forth is disposed in the center of a substantially parallelepiped-shaped cavity. These plural resonance modes are utilized.

Abstract: An inner conductor comprising high impedance portions and low impedance portions alternately connected to each other is disposed in the center of an outer conductor having a substantially square cross-section. Two holes are formed in one side of the outer conductor so as to extend through the wall of the outer conductor. A substantially &pgr;-shaped coupling line comprising a main line portion and probe-connecting portions is formed on the surface of a dielectric substrate. Probes made of conductor rods are connected at the ends, respectively. A resistor is provided at one end of the main line of the coupling line. The other end of the main line functions as an output terminal, and can be connected to an external circuit. The probes are inserted through the holes. The dielectric substrate is disposed inside of the outer conductor at predetermined positions.

Abstract: A dielectric filter that has attenuation poles on both the low frequency side and the high frequency side of its pass band, without using two dielectric resonators. The dielectric filter includes a cavity in which a conductive layer is formed, and a cross-shaped dielectric resonator disposed within the cavity, the dielectric resonator having at least three resonant modes, and coupling loops being coupled to the dielectric resonator. A coupling loop couples to a resonant mode at a first stage, among the resonant modes of the dielectric resonator, and also couples to resonant mode at a third stage in approximately negative-phase with respect to the first stage.

Abstract: In a high-frequency circuit having a substrate having a high-frequency transmission line and an dielectric resonator formed on said substrate so that said dielectric resonator and said high-frequency transmission line may be coupled electro-magnetically to each other, a hole part or a cavity part is formed at a part of said substrate and a dielectric resonator is embedded in said hole part or said cavity part. In the same object, a high-frequency circuit having a dielectric resonator is produced by the step for forming a high-frequency transmission line on a substrate, the step for forming a hole part or a cavity part on a part of the substrate, and the step for mounting a dielectric resonator in the hole par formed on the surface of the substrate.

Abstract: A dielectric resonator filter comprises dielectric resonators, an enclosure having a main body, a lid, and partition walls, interstage-coupling tuning windows, interstage-coupling tuning bolts, input/output terminals, and input/output coupling probes. Resonance-frequency tuning members each composed of a conductor plate and a bolt coupled integrally thereto are attached to the enclosure lid. Undesired-mode suppressing means such as rings attached to the bolts of the resonance-frequency tuning members or bolts attached to the conductor plates or to the enclosure lid are disposed in an undesired-mode excitation space, whereby the occurrence of a disturbed characteristic in the pass band (or stop band) is suppressed.

Abstract: A TE dual-mode resonator is provided. The TE dual-mode resonator has first and second modes. The resonator includes an enclosure having a cavity with an interior surface. The resonator further includes a dielectric resonator body, having a central portion with a plurality of members extending outwardly from the central portion. The dielectric resonator body is coupled directly to the interior surface.

Abstract: A dielectric resonator (10) having three surfaces formed by chamfering three ridged portions sharing an apex of a dielectric block and another three surfaces adjacent respectively thereto, in which each of the chamfered surfaces and the adjacent surfaces thereto offers an angle of 45 degrees and an area ratio of the chamfered surfaces with respect to the adjacent surfaces is 45% is mounted in a cut-off waveguide of a generally rectangular parallelopiped (21) and feeding probe (24) and (25) are provided for composing a dielectric filter.

Abstract: A resonator having a dielectric element, a metal housing accommodating the dielectric element, and a low relative permittivity material holding the dielectric element so as to have a predetermined clearance generated between a dielectric element surface of the dielectric element to which a generated electric field is substantially orthogonal and a housing surface of the metal housing opposed to the dielectric element surface.

Abstract: The dielectric porcelain of the present invention comprises a polycrystalline material of which a main component comprises oxides containing at least a rare earth element (Ln), Al, M (M represents Ca and/or Sr) and Ti as metal elements, wherein the thickness of a grain boundary layer is 20 nm or less, thereby achieving a high value of &egr;r, high Q factor and small absolute value of the temperature coefficient &tgr;f of resonant frequency in a high frequency region. Thus this dielectric porcelain is preferably used in dielectric resonators.

Abstract: A multi-mode resonator device can be reduced in size even while increasing the number of resonators while including either a semi-coaxial resonator or a coaxial resonator. Coupling between a TEM mode as a resonance mode of the semi-coaxial resonator and a TM mode as another resonance mode can be facilitated, which enables coupling between the resonators at a predetermined coupling strength. Inside a cavity with a cover, a conductive rod and a dielectric core are disposed so as to substantially equalize a quasi-TEM-mode resonant frequency generated by the cavity and the conductive rod and a quasi-TM-mode resonant frequency generated by the cavity and the dielectric core. A coupling adjusting block is arranged at a place where the magnetic field of one of two coupling modes generated by the quasi-TEM and quasi-TM modes is strong and that of the other mode is weak. The invention also provides a filter, duplexer, and a communication apparatus using the resonator device.

Abstract: A planar circuit has a substrate, a planar circuit conductor disposed on a first main surface of the substrate, a ground conductor disposed on a second main surface of the substrate for creating a high frequency resonator based on an electromagnetic wave field in cooperation with the planar circuit conductor, and a circuit element disposed on an opening formed in at least one of the planar circuit conductor and ground conductor to electronically control the electromagnetic wave field. The circuit element may be a variable reactance element such as a varactor diode, or a switching element. The circuit element can variably control the electromagnetic wave field which defines the resonator, so that the resonator can be controlled, for example, to resonate at a variable frequency.

Abstract: The resonator of the present invention includes a cylindrical dielectric and a conductor film covering the surface of the dielectric in close contact therewith. The conductor film is constructed of a cylindrical portion and two flat portions, and is formed by subjecting the surface of the dielectric to metallization or the like. With the conductor film formed in close contact with the dielectric, deterioration of the Q value and the like caused by instability of connection at the corners can be suppressed even when a radio frequency induced current flows from the cylindrical portion over the two flat portions.

Abstract: An open loop resonator filter employed aperture on the ground plane is disclosed. The open loop resonator filter using apertures on the ground plane formed on the dielectric substrate, the open loop resonator filter including: one or more open loop resonators formed on a upper side of the dielectric substrate and implemented by microstrip lines; and one or more apertures formed on a predetermined area of the ground plane. The present invention can control the coupling coefficient of the open loop resonator without degrading the group delay characteristics by forming the aperture on the ground plane. Therefore, by forming the aperture on the ground plane, it is possible to design a filter having a wide bandwidth characteristic.