Abstract: Novel structures and methods for forming useful high temperature superconducting devices, most particularly resonators, are provided. Structures resulting in reduced peak current densities relative to known structures achieve numerous desirable benefits, especially including the reduced intermodulation effects of earlier resonators. In one aspect of this invention, a spiral in, spiral out resonator is provided, characterized in that it has an odd number of long runs, at least equal to five long runs, where the long runs are connected by turns, and wherein there are at least two sequential turns of the same handedness, followed by at least two turns of the opposite handedness. In yet another aspect of this invention, it has been discovered that reducing the size of the input and output pads of HTS resonators increases the relative inductance compared to the capacitance. Yet another resonator structure is a spiral snake resonator having a terminal end disposed within the resonator.

Abstract: A dished head and a wall part are integrally formed in one body by spinning, using a flat aluminum based material, and then a corrosion-proof protective coating is formed on the whole surface by the Irridite process to complete the canister. The combination of appropriate material selection and production process saves the processing time (man-hour) needed for forming resonator canisters and its surface treatment, improves the thermal conductivity, and consequently decreases individual differences of the radio frequency loss in resonator canisters.

Abstract: A semiconductor switching circuit device includes a field effect transistor having a source electrode, a gate electrode and a drain electrode, a first electrode pad connected to the source electrode or the drain electrode, and a second electrode pad connected to the source electrode or the drain electrode which is not connected to the first electrode pad. The device also includes a third electrode pad receiving a DC voltage and applying the DC voltage to the field effect transistor, a first insulating layer covering the field effect transistor, a metal layer disposed above the first insulating layer and connected to the third electrode pad, and a second insulating layer disposed on the metal layer. The third electrode pad may be a control terminal pad, a ground terminal pad or a terminal pad receiving a constant DC power voltage. The metal layer may be a flat sheet, a lattice or a comb-like structure.

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 microstrip resonator including a dielectric substrate, a resonance electrode on a first main surface of the dielectric substrate, and a ground electrode over an entire second main surface of the dielectric substrate. The resonance electrode includes a superconducting film and a metal film deposited in that order. The ground electrode includes a superconducting film and a metal film deposited in that order. The superconducting film functions as an electrode in low-temperature operation below a critical temperature, and the metal film functions as an electrode in high-temperature operation at or above the critical temperature. The length of the superconducting film of the resonance electrode is set to be longer than that of the metal film of the resonance electrode, so that the resonance frequency in low-temperature operation is substantially equal to the resonance frequency in high-temperature operation.

Abstract: In a resonator having a dielectric member and an electrode formed on the dielectric member, a displacement area (D area) having a high vertical electric field component, and a short or steady area (S area) having a vertical electric field component of zero or close to zero are provided in an interface between the dielectric member and the electrode. A single-layer conductive film divided into portions is formed in the D area or on the side surfaces of the dielectric member, and a multilayer thin-film electrode is formed in the S area or on the end faces of the dielectric member. Conductive thin films of the multilayer thin-film electrode are alternately connected to the single-layer conductive film portions. In-phase currents having the same amplitude flow to the conductive thin films of the multilayer thin-film electrode in the S area in radial direction with respect to the axis of symmetry, thus achieving low-loss operation of the multilayer thin-film electrode in the S area.

Abstract: A bandpass filter disposed on a substrate includes one pair of ring Each of the ring resonators includes a pattern inductor, a resonance capacitor connected in parallel with the pattern inductor, and an input/output terminal connected with the pattern inductor via a coupling capacitor. The pattern inductors are connected with an impedance varying device, whereby the bandpass filter is capable of frequency adjustments.

Abstract: The present invention incorporates triple-mode, mono-block resonators that are smaller and less costly. The size reduction has two sources. First, the triple-mode mono-block resonator has three resonators in one block. This provides a 3-fold reduction in size compared to filters currently used which disclose one resonator per block. Secondly, the resonators are not air-filled coaxial resonators as in the standard combline construction, but are dielectric-filled blocks. The coupling between modes is accomplished by the corner cuts. One oriented along the Y axis and one oriented along the Z axis. In addition, a third corner cut along the X axis can be used. Corner cuts are used to couple a mode oriented in one direction to a mode oriented in a second mutually orthogonal direction. Each coupling represents one pole in the filter's response. Therefore, the triple-mode mono-block discussed above represents the equivalent of three poles or three electrical resonators.

Abstract: The idea of the invention is to fabricate a multilayer coaxial transmission line into a printed circuit. The outermost conductor is fabricated by conductive conduit strips in different layers, using conductive via posts in isolation layers connecting the strips. The innermost conductor can be a single conductive strip or multiple strips in different layers connected together through conductive via posts.

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: A conductive film is provided on a dielectric substrate. The conductive film has conductor opening portions, which serve as inductive regions, and a conductor opening portion, which serves as a capacitive region. Multi-step ring resonator elements, each including a conductor line aggregate, are provided on respective substrates to configure resonator elements. The resonator elements are mounted above the conductor opening portions that serve as the inductive regions. This arrangement provides a resonator having a high Qo.

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: A dielectric filter and a dielectric duplexer have structures for coupling between resonators, in which a range for determining the coupling strength between the resonators can be broadened and the polarity of the coupling can be changed. In addition, a communication apparatus incorporating the dielectric filter or the dielectric duplexer can be provided. Inside a dielectric member, resonance line holes having resonance lines formed on the inner surfaces thereof are disposed. Both ends of each of the resonance line holes are open-circuited. The inner diameter of each of the resonance line holes is changed at some point in the longitudinal direction of each resonance line to form a stepped part.

Abstract: A multi-spiral element includes a group of spiral conductive lines arranged so as not to cross each other so that the spiral conductive lines are substantially rotationally symmetric with respect to a predetermined point on a dielectric substrate. A plurality of conductive lines in the group of spiral conductive lines have external peripheral ends aligned at a substantially straight line substantially orthogonal to the group of spiral conductive lines. The external peripheral ends of each of the plurality of conductive lines in the multi-spiral element are connected to respective ends of a straight-line-group element having a group of parallel straight conductive lines. A resonator includes the multi-spiral elements functioning as capacitors for accumulating a charge, and the straight-line-group element functioning as an inductor.

Abstract: A dielectric resonator includes a slot line constructed by providing a slot electrode having a spiral slot at either an external face of a dielectric layer or inside the dielectric layer and a shielding conductor provided at a predetermined distance from the slot electrode. The slot line is employed as a resonant line so as to provide a dielectric resonator, an inductor, a capacitor, a dielectric filter, an oscillator, and/or a communication device.

Abstract: A transmission line configured as a looped-stub resonator is disclosed, which can be used as a frequency selective element for an oscillator, such as a VCO of a phase locked loop. The transmission line is a fraction of an electrical wavelength, and can be embedded to provide an inner resonant layer of an overall layered structure. The transmission line is formed into a loop or multiple loops and may be terminated with a capacitor, short circuit, or open circuit. In the embedded case, dielectric insulating material can be used to surround the transmission line on top and bottom surfaces as layers. In addition, electrically conducting material layers can be used to surround the dielectric insulating material.

Abstract: A filter has coupled pairs of resonators positioned between and planar to split feed lines. The filters are further positioned orthogonal to the signal path. The filter has two pairs of resonators. Coupling extensions of the split feed lines are substantially parallel to each other. The resonators couple with the split feed lines at the coupling extensions. The resonators in each pair also couple to each other. The topology effectively forms an Elliptic Function response bandpass filter with high close-in frequency rejection capability. The filter can be cascaded to provide improved frequency rejection. Further, this topology may be relatively inexpensively produced using standard lithography techniques.

Abstract: The concept of electromagnetic bandgaps (EBG) is used to develop a high quality filter that can be integrated monolithically with other components due to a reduced height, planar design. Coupling adjacent defect elements in a periodic lattice creates a filter characterized by ease of fabrication, high-Q performance, high port isolation and integrability to planar or 3-D circuit architectures. The filter proof of concept has been demonstrated in a metallo-dielectric lattice. The measured and simulated results of 2-, 3- and 6-pole filters are presented at 10.7 GHz, along with the equivalent circuits.

Abstract: A resonator and filter including the resonator is disclosed. The resonator (100) includes an open conductive loop (100) with folded transmission line segments (124, 134) extending from the adjacent ends of the loop. Of each transmission line segment, the portion emanating from the respective end of the loop is positioned generally along-side the corresponding portion of the other transmission line segment. That is, the two transmission line segments are folded away from each other. The resonator can be generally elongated in shape, with the loop at one end of the long axis and the transmission line segments at the other. The transmission line segments occupy a footprint (W2) that is not substantially greater than the width of the loop (W1). The filter includes multiple resonators of the invention, each resonator being coupled to at least another or the resonators. The resonators can be positioned in a side-by-side fashion, with the long axes of the resonators parallel or anti-parallel to one another.

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: An “inside out” process is used to make RF antennas and components or higher frequency components and/or optics. An electroformed single or multi layer of metal, such as copper, is applied to a reusable or disposable mandrel. Additional metal or composite components and/or pieces may be attached to the electroform by means of further electroforming, and/or applying adhesive and/or soldering. Any composite material (for example, fiberglass or carbon fiber reinforced plastic) is then applied selectively or uniformly around the electroform and/or additional components for structural reinforcement, and/or enhancement of thermal stability and/or thermal conductivity. The mandrel is then removed by physical or chemical means. Adhesion over temperature and humidity extremes, surface finish, uniform metalization thickness, and surface electrical conductivity are all vastly improved over equivalent electroplated composites.

Abstract: A high frequency filter kit in which resonating first and second electrical circuits are enclosed between proximal and distal ends of a filter case. Partitioning the inside of the enclosed resonant circuits may be performed by a user to form at least a first cavity and a second cavity. The first resonating circuit is then disposed inside the first cavity of the filter case extending from the proximal end towards the distal end, and the second resonating circuit is disposed inside the second cavity also extending from the proximal end towards the distal end. Electrical signals are coupled into the resonating circuits by an encased signal coupler which is removably mounted by a coupling housing for supporting the signal coupler at the proximal end of the filter case for positioning in the vicinity of the resonating circuits.

Abstract: A cost-effective communication filter is prepared by etching the surfaces of a shaped and fired ceramic core, applying an electroless nickel solution to create a nickel layer of limited thickness, electroplating the nickel plated core with a silver layer, patterning the nickel and silver plated core by removing metallization from selected surface areas and then heating the patterned filter block to bond the metal layers. The resulting filters comprise a rigid dielectric core defining a plurality of through-hole passages extending between opposing sides of the core. Present on the core is a pattern of metallized and unmetallized regions wherein the metallized regions of the pattern include an inner layer of nickel and an outer silver-containing layer.

Abstract: A component that includes a first structure that is integrated with a second structure. The first structure is a lumped balanced to unbalanced circuit (balun) and the second structure is a resonator-based filter. The function of the balun is to move a signal from a differential form to a single ended form or from a single ended form to a differential form. The component has an area that is comparable to the area needed to implement the balun alone. However, the component now provides a filter function. Preferably, the substrate of the first structure also acts as a substrate for the second structure.

Abstract: The invention relates to a dielectric double-mode resonator of a radio-frequency filter that comprises a block structure comprising at least two resonator structures having at least one resonance mode each. In addition, said block structure comprises a cavity wall that limits a cavity at least partly inside the block structure, the cavity affecting the resonance modes of the at least two resonator structures. The block structure comprises a first block and a second block set against each other and each comprising at least part of the at least two resonator structures and at least part of the cavity wall limiting the cavity.

Abstract: A method of fabricating an encapsulated micro electro-mechanical system (MEMS) and making of same that includes forming a dielectric layer, patterning an upper surface of the dielectric layer to form a trench, forming a release material within the trench, patterning an upper surface of the release material to form another trench, forming a first encapsulating layer that includes sidewalls within the another trench, forming a core layer within the first encapsulating layer, and forming a second encapsulating layer above the core layer, where the second encapsulating layer is connected to the sidewalls of the first encapsulating layer. Alternatively, the method includes forming a multilayer MEMS structure by photomasking processes to form a first metal layer, a second layer including a dielectric layer and a second metal layer, and a third metal layer. The core layer and the encapsulating layers are made of materials with complementary electrical, mechanical and/or magnetic properties.

Abstract: A high-frequency filter for use in a superhigh frequency band such as of microwaves and millimeter waves has a substrate, a metal conductor disposed on a first main surface of the substrate, a resonator comprising a transmission line of a coplanar structure which is made of the metal conductor, and input and output lines disposed on a second main surface of the substrate transversely across the resonator and electromagnetically coupled to the resonator. The resonator may be a coplanar line resonator (coplanar waveguide resonator) or a slot line resonator. The high-frequency filter has a steep attenuating gradient in filter characteristics. The high-frequency filter may be combined with variable-reactance devices such as variable-capacitance diodes for electronically controlling the filter characteristics.

Abstract: A microstrip line includes a strip conductor, a line electrode, and edge electrodes provided at the edges on both sides of the line electrode. The construction of the microstrip line greatly reduces the edge effect of the line electrode and decreases the conductor loss of the line electrode.

Abstract: The present invention relates to a tunable resonating arrangement comprising a resonator apparatus (10), input/output coupling (4) means for coupling electromagnetic energy into/out of the resonator apparatus, and a tuning device (3) for application of a biasing voltage/electric field to the resonator apparatus. The resonator apparatus comprises a first resonator (1) and a second resonator (2). Said first resonator is non-tunable and said second resonator is tunable and comprises a ferroelectric substrate (21). Said first and second resonators are separated by a ground plane (13) which is common for said first and second resonators, and coupling means (5) are provided for providing coupling between said first and second resonators. For tuning of the resonator apparatus, the biasing voltage/electric field is applied to the second resonator (2).

Abstract: A band-pass filter functioning as a electronic chip component includes a chip having upper and lower surfaces, a pair of side surfaces, and first and second end surfaces facing each other. A resonator electrode is disposed in the chip. The band-pass filter also includes input and output electrodes extending in the vertical direction, which are coupled or connected to the resonator electrode, and a tubular first ground electrode surrounding the chip so as to enclose the resonator electrode. The input and output electrodes are disposed at end portions or inner sides of the tubular portion so as not to be electrically connected to the first ground electrode. The band-pass filter further includes two pairs of second ground electrodes which are disposed on both sides of the input electrode and/or output electrode and which are electrically connected to the first ground electrode.

Abstract: A closed conductive loop for use in planar circuits to realize shunt capacitors instead of conductive patches is disclosed. The closed conductive loop may be formed on a planar substrate or extend to multiple conductive layers in a multi-layer circuit. The use of closed conductive loops as shunt capacitors offers possibilities of more flexible circuit layout, reduced circuit footprint and comparable or improved performance as compared to using conductive patches as shunt capacitors.

Abstract: Composite media having simultaneous negative effective permittivity and permeability over a common band of frequencies. A composite media of the invention combines media, which are either themselves separately composite or continuous media, having a negative permittivity and a negative permeability over a common frequency band. Various forms of separate composite and continuous media may be relied upon in the invention. A preferred composite media includes a periodic array of conducting elements that can behave as an effective medium for electromagnetic scattering when the wavelength is much longer than both the element dimension and lattice spacing. The composite media has an effective permittivity &egr;eff(&ohgr;) and permeability &mgr;eff(&ohgr;) which are simultaneously negative over a common set of frequencies. Either one or both of the negative permeability and negative permittivity media used in the invention may be modulable via external or internal stimulus.

Abstract: The present invention comprises baluns 2a, 2b which convert balanced line signals and unbalanced line signals mutually, and filters 3a, 3b which are electrically connected to the baluns 2a, 2b and pass or attenuate the predetermined frequency bands. Electrode layers 15a-22a, 25a, 41, 42, 43 which compose the electrode patterns of the baluns 2a, 2b and the filters 3a, 3b, and the dielectric layers 30-39 are integrally stacked.

Abstract: Voltage fluctuations, especially due to a resonant effect of a power distribution system, result in serious timing skews in a high-speed digital system. Adding extra resistive loadings for coupling out the noise into external terminations will reduce a quality factor of the power distribution system, which will effectively minimize the noise accumulation. The external coupled resistive terminators are preferably formed on positions of a microstrip resonator where relatively high noise fluctuations occur. Each of the external coupled resistive terminators may be formed of a resistor, a transmission line with a resistor at one end, a lossy transmission line with an open circuit at one end, or a quarter-wavelength lossy transmission line. Simulation results indicate that the maximum voltage fluctuations are suppressed from 750 mV to 150 mV at a resonant frequency and about 50% for an overall range of the operating frequencies.

Abstract: The invention is a method and apparatus for coupling energy into or out of a dielectric resonator circuit by means of a coupling loop. More particularly, the invention is a method and apparatus for adjustably mounting a coupling loop relative to a resonator, the method and apparatus particularly adapted for use with conical and similar resonators in which the field of interest, typically the TE mode, varies as a function of longitudinal position relative to the resonator.

Abstract: A high frequency filter design for the GHz frequency range is provided. The high frequency filter comprises at least a microstrip design that incorporates both transverse and lateral couplings between the filters resonators. The high frequency filter further incorporates an opened or fully enclosed enclosure over the strip line or microstrip circuitry and may be manufactured on a relatively thick dielectric substrate having a thickness that is greater than about a twentieth of the filter's band-pass wavelength in the dielectric substrate. The high frequency filter design provides a small, easily reproducible filter design better than prior art microstrip filters.

Abstract: A dual mode band-pass filter includes a metallic film for defining a resonator, disposed on the first main surface of a dielectric substrate having first and second main surfaces, or inside of the dielectric substrate. An opening is formed in the metallic film. At least one ground electrode is provided on the second main surface of the dielectric substrate or inside of the dielectric substrate, so as to be opposed to the metallic film through a dielectric layer. A pair of input-output coupling circuits is connected to the metallic film.

Abstract: By using a method for manufacturing a dielectric laminated device, an opening is formed on a first dielectric sheet, a strip line and an input and output line including an input and output electrode are formed by burying electrode materials in said opening, the first dielectric sheet is laminated with the second and third dielectric sheets disposed above and below respectively to form a laminate, a first and second shield electrodes and a ground electrode are formed, an end of the strip line is connected to the ground electrode, the first shield electrode and the second shield electrode are mutually connected through the ground electrode, and the input and output electrode is exposed along the line direction of the strip line. By this constitution of the above dielectric laminated device, the mounting reliability of the dielectric laminated device can be further increased.

Abstract: A space is defined in a portion of an overlapping region where an open end portion of a resonant electrode and an inner-layer ground electrode, of a dielectric layer which is interposed between the resonant electrode and the inner-layer ground electrode. A space is defined in a portion of an overlapping region where the open end portion of the resonant electrode and another inner-layer ground electrode, of a dielectric layer which is interposed between the resonant electrode and the other inner-layer ground electrode. These spaces are filled with respective members having a dielectric constant higher than the dielectric layers.

Abstract: A high quality resonant circuit that can easily be integrated into an integrated circuit package or substrate is disclosed. The resonant circuit is based on a transmission line impedance transformation property, which allows the resonant circuit to have higher quality factor than existing integrated L-C implementations.

Abstract: A dual operation mode all temperature filter is provided. The dual operation mode filter is provided with a housing defining at least two cavities, an input port and an output port. It is also provided with a non-superconducting resonator disposed in a first one of the cavities and a superconducting resonator disposed in a second one of the cavities. The second resonator comprises a superconducting material containing 8-15% silver. The dual operation mode filter filters at a relatively high level at temperatures below a threshold temperature and at a lower, conventional level, at temperatures below the threshold.

Abstract: Single and multiple ferrite crystal resonator, oscillator, and filter coupling structures are disclosed. In one embodiment, a single ferrite crystal resonator coupling structure is configured as a single pole YIG-tuned-oscillator (YTO) coupling structure. The YTO coupling structure includes a circuit substrate having an upper and a lower side. The circuit substrate includes an aperture extending through the circuit substrate between first and second openings on the upper and lower sides, respectively. The aperture is configured to permit rotation of a ferrite crystal disposable at least partially therein about a plurality of axes whereby a desirable axis of the ferrite crystal is alignable with a magnetic field within the aperture. At least one coupling line through which an electric current can be directed, which extends between a first end and a second end of the first opening of the aperture across at least a portion of the first opening of the aperture.

Abstract: A printed circuit for processing radio frequency signals. The printed circuit includes a substrate. The substrate can be a meta material and can include at least one dielectric layer. The dielectric layer can have a first set of dielectric properties over a first region and a second set of dielectric properties over a second region. The dielectric permittivity and/or magnetic permeability of the second set of dielectric properties can be different than the first set of dielectric properties. The printed circuit also can include a single port resonant line and a ground coupled to the substrate. The dielectric properties can be controlled to adjust the size of the resonant line. The dielectric properties also can be controlled to adjust an impedance, quality factor and/or capacitance on the resonant line. Resonant characteristics of the resonant line can be distributed through the substrate.

Abstract: A method of producing a band-pass filter includes selecting the shape of a metallic film and the connection points of input-output coupling circuits such that first and second resonance modes are generated in a metallic film provided on a dielectric substrate. At least a portion of the resonance current or the resonance electric field in at least one of the resonance modes is made discontinuous such that the first and second resonance modes are coupled.

Abstract: A gradient coil structure for use in MRI apparatus has a main gradient coil 20 and a shielding coil 21, a portion of the shielding coil being disposed outwardly from the main coil. The coils are configured so that in a peripheral region 25 relative to the image region 22 the are almost coincident and the coils extend forwardly at an angle to the remainder of the main coil so that the main coil appears concave from the imaging region 22. This arrangement provides improved shielding efficiency.

Abstract: The invention provides a high frequency filter which can facilitate filter-characteristic adjustments and miniaturization and can obtain an excellent broadband characteristic. In addition, the invention provides a filter device using the high frequency filter, and an electronic apparatus incorporating the same. In this filter, a ground electrode is arranged on one of the main surfaces of a dielectric substrate. On the other main surface thereof there are arranged two or more microstrip lines, and one end of each microstrip line is grounded via a through-hole to form a high frequency filter. The microstrip lines and the shared through-hole constitute microstrip line resonators, which are coupled via the inductance of the through-hole. With this arrangement, there is no need for an additional coupling element. Thus, the size of the high frequency filter can be reduced. Furthermore, since a large coupling coefficient can be obtained, the high frequency filter can have a broadband characteristic.

Abstract: A dual mode band-pass filter includes a metallic film for defining a resonator, disposed on the first main surface of a dielectric substrate having first and second main surfaces, or inside of the dielectric substrate. An opening is formed in the metallic film. At least one ground electrode is provided on the second main surface of the dielectric substrate or inside of the dielectric substrate, so as to be opposed to the metallic film through a dielectric layer. A pair of input-output coupling circuits is connected to the metallic film.

Abstract: There is disclosed a half-wavelength (&lgr;/2) resonator which is constituted of a micro strip line or a strip line and in which line pattern portions are disposed symmetrically with respect to a reference line, connected to each other to form an L shape, and formed in an open loop shape so as to have open ends. For one pair of line pattern portions having the open ends, base portions connected to adjacent line pattern portions are disposed in the vicinity of the reference line, and the open ends are extended in opposite directions so that the ends are disposed apart from the reference line.

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 dual-mode resonator comprises a dielectric substrate having a region divided into four quadrants, and a ring resonator forming quadrangularly symmetrical configurations within the four quadrants of the region. The symmetrical configurations may be formed from folded sections of the resonator, so that parallel lines with opposite currents that cancel to minimize the far-field radiation of the filter structures. The symmetrical configuration can also be meandered, so that opposite currents in parallel line segments within each meander and the line segments that interconnect the meanders cancel to minimize the far-field radiation of the filter structures. One resonator can be used in a two-pole dual-mode filter structures, or multiple resonators can be used in more complex dual-mode filter structures.