Abstract: A variable radio frequency band filter includes a housing with a plurality of cavities, a plurality of resonators, wherein one resonator is arranged in each cavity, and a tuning arrangement having a plurality of tuning structures. One of the tuning structures is arranged in each of the cavities. The tuning structures of multiple cavities are mechanically connected such that the tuning structures may be shifted simultaneously in order to simultaneously vary the resonance frequencies of the cavities. Each tuning structure includes at least one first metallic surface facing the resonator and at least one second metallic surface facing a wall of the cavity, the first and second metallic surfaces being conductively connected. The second metallic surface is arranged such that a small and essentially uniform gap is formed between the second metallic surface and the wall to achieve a virtual grounding of the metallic surfaces.

Abstract: An apparatus for coupling a combline resonator and a ceramic resonator, including one or more of the following: a housing; a combline resonator in the housing; a ceramic resonator in the housing, the ceramic resonator having a stem portion and a mushroom portion; a ridge extending between the combline resonator and the ceramic resonator, the ridge passing between the mushroom portion of the ceramic resonator and the housing, wherein a coupling is obtained between an electrical field of the combline resonator and an electrical field of the ceramic resonator.

Abstract: A multiband filtering apparatus (40) for use in a communications system, said apparatus including a housing (21); a plurality of cavities (22.1, 22.2) disposed within said housing wherein each cavity includes a resonant structure, the resonant structure having at least one ceramic element (23.1, 23.2); at least one input port (27) coupled to a first resonator of said plurality of resonators; at least one output port (28) coupled to a second resonator of said plurality of resonators; and a closure member (25) adapted to engage said housing (21) and cap said cavities.

Abstract: A filter including at least two resonator through-holes defining apertures in the top surface surrounded by respective plates which in combination with associated through-holes define primary and secondary shunt zeros providing low ripple and high rejection adjacent the bandpass. In one embodiment, the through-hole of the primary shunt zero is coupled directly to an input/output pad, while the through-hole of the secondary shunt zero is indirectly coupled to the input/output pad via a coupling bar extending between the input/output pad and the secondary shunt zero. In another embodiment, the secondary shunt zero may be coupled directly to the input/output pad. In a further embodiment, additional resonator through-holes in combination with associated plates define additional shunt zeros coupled directly or indirectly to the input/output pad.

Abstract: A switch is replaced with a parallel resonant circuit 4. More specifically, a variable resonator includes a line part 1 that includes one or more lines and has an annular shape, at least two parallel resonant circuits 4 capable of changing a characteristic, and at least three variable reactance blocks 2 capable of changing a reactance value, in which the parallel resonant circuits 4 are electrically connected to the line part 1 at one end thereof at different positions on the line part 1, and the variable reactance blocks 2 are electrically connected to the line part 1 at predetermined intervals based on an electrical length at a resonance frequency.

Abstract: There is provided a signal processing method comprising: inputting an input signal having a certain band; dividing said input signal into a signal in a stop band and a signal in a pass band outside said stop band with a use of a band stop filter which has a center frequency of said input signal inside said stop band and includes a first resonator having said center frequency as a resonance frequency; extracting a signal in a desired band from the signal in said pass band with a use of a plurality of second resonators; decomposing the signal in said stop band into signals whose degeneracy of said resonance frequency are released; combining a degeneracy-released signals and the signal in said desired band to obtain a combined signal; and outputting the combined signal.

Abstract: A resonant element that causes a signal input from an input terminal to resonate at a predetermined resonance frequency and outputs it to an output terminal is provided. The element has a transmission line series including a plurality of transmission lines connected in series with each other and intersecting with a hotline connecting the input terminal and the output terminal and a plurality of switches. At least one of one end and the other end of the transmission line series is a grounded end. The resonant element having first and second end side, each end side having a first transmission line and a second transmission line connected to a switch having a grounded end. The resonance frequency is switched by turning on/off the switch to change the sum of the lengths of the transmission lines through which the signal passes.

Abstract: Various exemplary embodiments relate to a temperature compensation structure for use in a dielectric resonator that permits a support to be thermally efficient in rapidly transferring heat generated by a central puck in the resonator. The temperature compensation structure may have an extension shaped to promote heat from the puck into the support, thereby permitting high power operation of the dielectric resonator without overheating.

Abstract: There is provided a band pass filter including: a stacked body having a stacked structure of a plurality of dielectric sheets; and a plurality of elements provided in the stacked body, the plurality of elements including: a first capacitor electrode; a second capacitor electrode partially overlapping the first capacitor electrode to form capacitive coupling; a third capacitor electrode connected to the second capacitor electrode; a first inductor pattern having one end connected to the first capacitor electrode and the other end connected to a ground; a second inductor pattern having one end connected to the third capacitor electrode and the other end connected to the ground; an input terminal provided at one region of the first inductor pattern; and an output terminal provided at one region of the second inductor pattern.

Abstract: A delay filter module comprising at least one dielectric boneblack ceramic band pass filter and a circuit for compensating/equalizing the signal delay produced by the delay filter. In one embodiment, the circuit is defined by a hybrid coupler defining at least two ports coupled to a dielectric ceramic reactive termination block defining at least a pair of reactive termination resonators and coupling capacitors. The delay can be adjusted by tuning the dielectric boneblack band pass filter and/or the reactive termination resonators and/or the coupling capacitors defined by the dielectric ceramic reactive termination block.

Abstract: A medical device lead includes a conductor and one or more band stop filters. The conductor extends through a lead body and includes a proximal end and a distal end. The one or more band stop filters each have a first end and a second end and include a conductive coil. At least one of the first end and second end of each band stop filter is coupled to the conductor. A length of each band stop filter is such that, at magnetic resonance imaging (MRI) frequencies, the band stop filter phase shifts an MRI-induced signal on the conductor by 180° to attenuate the MRI-induced signal on the conductor.

Abstract: The electromagnetic filter according to the present invention includes a shield opening 102 provided in a shield conductor 101, a plurality of conductive strips 111 connected to the shield conductor 101 at both of two ends for dividing the shield conductor 101 into a plurality of divided openings 112, and a plurality of band-stop filters 113 located on each of the conductive strips 111 at a prescribed interval. By dividing the shield opening 102 into the plurality of divided openings 112, the amount of noise leaking via the shield opening 102 can be suppressed. Each of the band-stop filters 113 prevents a flow of an electric current of a prescribed frequency in each of the conductive strips 111, which would otherwise be caused by a magnetic field of the prescribed frequency passing the shield opening 102, and thus the wireless electric power transmission characteristic which uses coupling of magnetic fields of the prescribed frequency can be prevented from being deteriorated.

Abstract: A filter includes: an input terminal to which a fundamental wave signal and a harmonic signal group of the fundamental wave signal are supplied; an output terminal configured to output the fundamental wave signal supplied to the input terminal; a transmission line configured to connect the input terminal and the output terminal; an open-end stub configured to be provided corresponding to an odd harmonic signal among the harmonic signal group, coupled to the transmission line, and has a length corresponding to one quarter of a wavelength of the corresponding odd harmonic signal; a first short-end stub configured to be coupled to the transmission line and has a length corresponding to one quarter of a wavelength of the fundamental wave signal; and a second short-end stub configured to be coupled to the transmission line.

Abstract: A tuneable bandpass filter includes a plurality of coupled resonators. A common structure of the filter includes at least one common coupling or one common resonator. An upper loop includes first and second end resonators coupled together by a signal path and further includes at least one further signal path extending between end resonators. The further signal path includes at least one further resonator with the end resonators being coupled to the common structure. A lower loop includes first and second end resonators coupled together by a signal path and further includes at least one further signal path extending between end resonators. The further signal path includes at least one further resonator with the end resonators being coupled to the common structure.

Abstract: Various exemplary embodiments include a technique for tuning a filter to have two stop bands. This technique may involve combination of signals from a plurality of high-band notch resonators and low-band notch resonators. Loop wires may couple both high-band and low-band notch resonators to a central conductor, thereby enabling the central conductor to transmit a signal having dual stop bands.

Abstract: There is provided a filter which includes a transmission line, a stub branched from the transmission line, the stub electrically coupled with the transmission line, and a resonator configured to electromagnetically couple with the stub and to resonate at an odd harmonic frequency of a fundamental wave, the fundamental wave propagating through the transmission line.

Abstract: Disclosed is a printed circuit board including an electromagnetic bandgap structure. The electromagnetic bandgap structure, which includes a first dielectric material for interlayer insulation and is for blocking a noise, is inserted into the printed circuit board. The electromagnetic bandgap structure can include a first conductive plate, a second conductive plate arranged on a planar surface that is different from that of the first conductive plate, a third conductive plate arranged on a same planar surface as the first conductive plate, and a stitching via unit configured to connect the first conductive plate and the third conductive plate through the planar surface on which the second conductive plate is arranged. A second dielectric material having a permittivity that is different from that of the first dielectric material is interposed between any two of the first conductive plate, the second conductive plate, and the third conductive plate.

Abstract: Disclosed is a printed circuit board into which an electromagnetic bandgap structure for blocking a noise is inserted. The electromagnetic bandgap structure can include a first conductive plate, a second conductive plate arranged on a planar surface that is different from that of the first conductive plate, a third conductive plate arranged on a planar surface that is different from that of the second conductive plate, a connection pattern arranged on a planar surface that is different from that of the second conductive plate, a first stitching via unit configured to connect the first conductive plate to one end of the connection pattern through the planar surface where the second conductive plate is arranged, and a second stitching via unit configured to connect the third conductive plate to the other end of the connection pattern through the planar surface where the second conductive plate is arranged.

Abstract: A filter includes a first magnetic layer, a second magnetic layer, an insulating layer, a plurality of coils, a first non-magnetic layer and a second non-magnetic layer. The insulating layer is disposed between the first magnetic layer and the second magnetic layer, and the coils are disposed in the insulating layer. The first non-magnetic layer is disposed on one side of the first magnetic layer, which is far away from the insulating layer, and the second non-magnetic layer is disposed on one side of the second magnetic layer, which is far away from the insulating layer.

Abstract: A ceramic monoblock filter incorporating a top face input/output port metallization pattern defining an input/output transmission line, a power load distribution bar, and a ground plate. The transmission line, power load distribution bar, and ground plate are all positioned and oriented relative to each other and two of the resonators defining the filter to define load splitting capacitors providing increased power load handling characteristics.

Abstract: A method for forming a vertical coupling structure for non-adjacent resonators is provided to have a first and a second resonators, a dielectric material layer, a first and a second high-frequency transmission lines and at least one via pole. The first and the second resonators respectively have a first and a second opposite metal surfaces. The dielectric material layer is disposed between the opposite second metal surfaces of the first and the second resonators. The first and the second transmission lines are respectively arranged at sides of the first metal surfaces of the first resonator and the second resonator. The first high-frequency transmission line is vertically connected to the second high-frequency transmission line by the via pole.

Abstract: A filter includes a cross-coupling link which includes a crossbar, a first vertical support attached to one end of the crossbar, a second vertical support attached to another end of the crossbar, a first coupling arm attached to the first vertical support, a second coupling arm attached to the second vertical support, a first adjustable support attached to the first coupling arm at one end and grounded at another end, and a second adjustable support attached to the second coupling arm at one end and grounded at another end.

Abstract: A filter circuit device includes a resonator unit configured with six or more resonators, the resonators being divided into a first resonator group including resonators connected in parallel and having odd-numbered resonance frequencies and a second resonator group connected to the first resonator group in parallel and including resonators connected in parallel and having even-numbered resonance frequencies, a delay unit connected between the first and second resonator groups to make a phase difference in a range of (180±30)+360×j degrees (j is a natural number) between the first and second resonator groups, a power dividing unit configured to divide a power to the resonators, and a power combining unit configured to combine outputs of the resonators of the first and second resonator groups between which the phase difference is made.

Abstract: An object of the present invention is to provide an improved and simplified filter assembly. The object is achieved by a dielectric rod (120, 610, 620) for a filter chassis (110). The dielectric rod (120, 610, 620) extends between a first end (121) and a second end (122). The dielectric rod (120, 610, 620) comprises a conductive element (150) placed at the first (end 121). The conductive element (150) is adapted to be in conductive contact with a first contact means (141) of the filter chassis (110). The dielectric rod further comprises a second fastening element (160) placed at the second end (122). The second fastening element (160) is adapted to be attached and detached to a first fastening element (131) comprised in the filter chassis (110), such that the dielectric rod (120, 610, 620) is replaceable in the filter chassis (110).

Abstract: An apparatus 100 comprising a radiofrequency filter body housing 102. The radiofrequency filter body housing includes a polymeric composition 110 that includes at least one polymer foam 115 and filler material 120. The filler material is uniformly distributed and randomly oriented throughout the polymeric composition. The radiofrequency filter body housing also includes an electrically conductive material 125 coating the polymeric composition.

Abstract: A high-frequency filter arrangement comprising at least one filter consisting of a plurality of high-frequency inter-coupled cavities in which a locally fixed respective dielectric resonator element is disposed and in which a respective dielectric body can be modified, in order to tune the frequency of the filter, in the position thereof in relation to the dielectric resonator element. The structure of the inventive filter arrangement is simple, compact and economical and excellent filter and tuning properties are obtained by virtue of the fact that the dielectric body is arranged in an eccentric recess of the dielectric resonator element and that the dielectric body is rotatably arranged in the eccentric recess.

Abstract: The invention refers to a system and method to tune a multicavity filter of microwave signals, said filter comprising a filter body (CF), a removable lid (CO), n resonant cavities dug out in said filter body (CF) and n tuners (TU) susceptible of displacement under the action of movement means. Typically a sub-system to absorb the oscillations and vibrations generated in such displacements is associated to each tuner.

Abstract: In resonant elements 102 to 105 constituting a resonant circuit, an uncontrolled cross coupling which exists between two resonant elements is controlled by using a coupling element 106 which is newly arranged between the resonant elements, whereby it is possible to create a state where two resonant elements are not coupled with each other or a state where the amount of the coupling is reduced, which states are difficult to be realized on a plane. As a result, it is possible to improve characteristics of a planar filter.

Abstract: A dielectric filter having a dielectric block disposed on a mount board. The dielectric block includes inner conductor holes having open ends on the front surface of the dielectric block. Input/output electrodes are disposed on the undersurface of the dielectric block. Each of the input/output electrodes extends from the boundary between a side surface and the undersurface of the dielectric block to the boundary between the front surface and the undersurface of the dielectric block. An outer conductor includes undersurface electrode corner portions and an undersurface electrode main portion. Each of the undersurface electrode corner portions is disposed at a corner formed by the front surface and one of the side surfaces of the dielectric block.

Abstract: The invention relates to a tunable ?/4-filter subassembly whose frequency response can be adjusted. For this purpose, the ?/4-filter subassembly has a signal-conducting electrical conductor and an electrically conductive element that is at a reference potential. Furthermore, at least one short-circuit device is provided that electrically contacts the electrical conductor. An electrical coupling device is provided that couples the short-circuit device at a settable contact position to the electrically conductive element, wherein the electrical coupling device and the short-circuit device are movable relative to each other in order to set the length of the short-circuit device.

Abstract: A dielectric resonator is constructed so as to have a substantially cruciform shape in cross section by including four plate components. A first set of opposed plate components have respective first principal center planes separated from each other and substantially parallel with each other. A second set of opposed plate components also have respective second principal center planes separated from each other and substantially parallel with each other. The first principal center planes are orthogonal to the second principal center planes. With this configuration, a TE01?y mode in which an electric-field vector rotates within the first set of opposed plate components and a TE01?z mode in which an electric-field vector rotates within the second set of opposed plate components are coupled.

Abstract: A filter for processing an RF signal includes an input port and an output port and a plurality of resonators. The resonators are arranged in a sequentially-coupled arrangement between the input and output ports to affect an RF signal therebetween. Each resonator includes a cavity and resonant element. The resonant elements of at least two resonators are made of two different types of materials to effect higher and lower Q factors for the resonators. The resonators are arranged to provide at least one resonator having a lower Q factor proximate one of the input and output ports while the higher Q factor resonator is provided proximate the inside of the sequentially-coupled arrangement.

Abstract: A combline filter has a ceramic resonator disposed inside at least one cavity wall. Because the resonator is implemented as a hollow rod, a tuning element may be inserted into an opening on the top of the rod to tune its frequency. A mounting element, inserted into an opening on the bottom of the rod secures its position inside a cavity resonator. Instead of soldering the resonator to the filter's walls, the resonator is supported above a bottom or side wall of the cavity resonator.

Abstract: A cavity microwave filter assembly for filtering an electromagnetic wave including a plurality of cavity resonator assemblies, where each cavity resonator assembly has a bottom and including at least one lossy element for electromagnetically coupling two elements of the filter assembly, where at least one element is a cavity resonator assembly. The lossy elements provide attenuation in the loss variation of the filter and sharper slopes resulting in an improved Q factor for the filter. A method for realizing lossy elements as resistors requires determining an equivalent circuit model that can be manufactured using resistors, coupling elements, and transmission lines. The method includes representing the resistive element with a resistor, unity admittance inverters and coupling elements and then scaling to determine the resistor and coupling values. The method further includes replacing the admittance inverters with transmission lines of the appropriate length to account for the specific design of the filter.

Abstract: A dielectric filter having inner-conductor holes penetrating through a dielectric block from a first surface to a second surface thereof. An outer conductor and input/output electrodes are formed on an outer surface of the dielectric block. A side of each of the input/output electrodes facing the first surface is substantially in parallel to the first surface, and an intersection of a side facing the second surface and a side facing a sixth surface is tapered. With such a configuration, an attenuation characteristic at an attenuation band is improved by making the attenuation characteristic less likely to receive an influence of a TE mode.

Abstract: A triple-mode filter is disclosed, the triple-mode filter including a cavity for confining electromagnetic waves and a metallic block acting as a resonator within that cavity. The metallic block does not contact the conductive walls of the cavity, but is instead suspended by a support element. Triple-mode resonators may be combined to produce bandpass filters having three or more poles. In other configurations, triple-mode cavity metallic resonators may be coupled to triple-mode cavity ceramic resonators or to combline resonators to achieve various filtering functions and performances suitable for different applications.

Abstract: An electromagnetic bandgap structure includes: first conductive plates, placed on a first planar surface; second conductive plates, placed on a second planar surface; a first conductive trace, electrically connecting any two adjacent first conductive plates with each other on the first planar surface, in which the two adjacent first conductive plates are in a first direction; a second conductive trace, electrically connecting any two adjacent second conductive plates with each other on the second planar surface, in which the two adjacent second conductive plates are in the first direction; a first stitching via, electrically connecting any two adjacent conductive portions lined up in a direction different from the first direction on the first planar surface with each other; and a second stitching via, electrically connecting any two adjacent conductive portions lined up in a direction different from the first direction on the second planar surface with each other.

Abstract: An electromagnetic bandgap structure includes: first conductive plates, placed on a first planar surface, in which the first conductive plates are lined up in a first direction; second conductive plates, placed on a second planar surface and arranged at an area corresponding to an area in which the first conductive plates are disposed, in which the second conductive plates are lined up in the first direction; a first stitching via, electrically connecting any two adjacent conductive portions with each other and in which the two adjacent conductive portions are lined up in a direction that is different from the first direction on the first planar surface; and a second stitching via, electrically connecting any two adjacent conductive portions with each other and in which the two adjacent conductive portions are lined up in a direction that is different from the first direction on the second planar surface.

Abstract: An embodiment of the present invention provides an apparatus, comprising a filter; and a matching network coupled to the filter, the matching network including a plurality of voltage tunable dielectric varactors.

Abstract: To reduce emission of an unintentional electromagnetic wave even if a frequency of a clock signal being output is high, a printed circuit board (10) includes: a substrate (101); signal output circuits (102 and 103) formed on the substrate (101), for outputting a clock signal; power supply wirings (109 and 110) for connecting the signal output circuits (102 and 103) and a power source; and trap filters (107 and 108) provided to the power supply wirings (109 and 110), for attenuating a frequency component corresponding to a frequency of the clock signal.

Abstract: The invention is a dielectric resonator circuit comprising a housing; first, second, and third resonators positioned substantially in a row within the housing with said second resonator positioned between the first and third resonators, wherein the resonators are positioned relative to each other such that a field generated in each resonator couples to an adjacent resonator; wherein the housing encloses the resonators and has a separating wall positioned between the first and third resonators in order to control electromagnetic coupling between the first and third resonators; and wherein said first separating wall comprises a first end and a second end along a length thereof and wherein the separating wall defines an iris at the first end, the wall comprising a main wall portion positioned substantially between the first and third resonators and an extension wall portion at the first end that extends at an angle from the main wall portion of said wall.

Abstract: A superconductive filter includes a superconductive filter substrate having a dielectric substrate and a plurality of resonator patterns formed on a surface of the dielectric substrate, the plurality of resonator patterns including a superconductive material; a package accommodating the superconductive filter substrate; and an intermediate substrate disposed between an inner surface of the package and the superconductive filter substrate, and thermally coupling the package and the superconductive filter substrate wherein a difference between a degree of contraction of the intermediate substrate and the degree of contraction of the dielectric substrate is smaller than a difference between the degree of contraction of the dielectric substrate and the degree of contraction of the package, when the package, the intermediate substrate, and the dielectric substrate are cooled from room temperature to a critical temperature of the resonator patterns.

Abstract: In accordance with principles of the present invention, a two or more pole dielectric resonator circuit is provided with resonators that are elliptical in cross section orthogonal to the longitudinal axis. The resonators are mounted so that they are rotatable about their longitudinal axes, such that the straight line distance between two adjacent resonators measured in a straight line between orthogonal to and intersecting the longitudinal axes of the two resonators is a function of the orientation of the resonators about their longitudinal axes. The resonators can be oriented about their longitudinal axes in any orientation to adjust their spacing, which is directly proportional to their coupling magnitude, which, in turn, is proportional to the bandwidth of the circuit.

Abstract: An apparatus for coupling a combline resonator and a ceramic resonator, including one or more of the following: a housing; a combline resonator in the housing; a ceramic resonator in the housing, the ceramic resonator having a stem portion and a mushroom portion; a ridge extending between the combline resonator and the ceramic resonator, the ridge passing between the mushroom portion of the ceramic resonator and the housing, wherein a coupling is obtained between an electrical field of the combline resonator and an electrical field of the ceramic resonator.

Abstract: A notch filter suitable for attenuating certain frequencies of a radio-frequency signal includes an input for receiving the radio-frequency signal and an output for the output of a portion of the radio-frequency signal, first and second capacitive means, at least one inductor and a negative resistance circuit suitable for compensating the resistive losses of said at least one inductor. The inductor and the first and second capacitive means are placed to produce a resonator and the filter comprises a control device suitable for controlling the negative resistance circuit. The input impedance of the filter comprises a pole and a zero, with the pole depending on the second capacitive means and the zero depending on both the first and second capacitive means. The first and second capacitive means are variable and the control device is suitable for controlling the first and second capacitive means.

Abstract: In a dielectric filter (1) for base station communication equipment, a rectangular solid dielectric block (2) is provided with a plurality of ¼ wavelength resonators (3A1-3A4; 3B1-3B4), which are arranged along side planes (2c,2d) of the dielectric block and extend in parallel to each other and to the side planes (2c,2d). The dielectric block (2) is composed of dielectric ceramics having a relative dielectric constant of 5-20, and a size (H) in a direction orthogonally intersecting with the side planes (2c,2d) of the dielectric block (2) is 10-30 mm.

Abstract: An apparatus includes a radome and an evanescent wave-coupled windowing system in the radome. In operation, the apparatus receives radiation reflected from an object that is incident upon a windowing system; emits evanescent waves from the windowing system whose amplitudes are proportional to the angle of incidence of the radiation; and non-coherent, Fresnel direction finds the object.

Abstract: An antenna system includes a dielectric structure formed on a substrate; an antenna, partially within the dielectric structure, and supported by the dielectric structure; a reflective surface formed on the substrate. A shield blocks radiation from a portion of the antenna and from at least some of the dielectric structure. The shield is supported by the dielectric structure.

Abstract: A filtering circuit and a structure thereof are provided. The filtering circuit includes an input terminal, an output terminal, a resonant circuit, a first coupling portion, and a second coupling portion. The resonant circuit is coupled between the input terminal and the output terminal and includes M resonators which are arranged in sequence. A signal received by the input terminal can be transmitted to the output terminal by the resonant circuit through inter-coupling between adjacent resonators. The first coupling portion and the second coupling portion are respectively coupled to non-adjacent resonators. A part of the signal received by the input terminal is transmitted to the second coupling portion via the first coupling portion through cross-couple. Thereby, sideband interference can be further suppressed.

Abstract: A vertical coupling structure for non-adjacent resonators is provided to have a first and a second resonators, a dielectric material layer, a first and a second high-frequency transmission lines and at least one via pole. The first and the second resonators respectively have a first and a second opposite metal surfaces. The dielectric material layer is disposed between the opposite second metal surfaces of the first and the second resonators. The first and the second transmission lines are respectively arranged at sides of the first metal surfaces of the first resonator and the second resonator. The first high-frequency transmission line is vertically connected to the second high-frequency transmission line by the via pole.