Abstract: A differential transmission circuit includes a grounded conductive layer, a pair of transmission line conductors, a conductive film and a via hole which connects the grounded conductive layer to the conductive film. The differential transmission circuit further includes a straight-line region which is present in the differential transmission circuit through which a differential transmission signal output by a driving circuit is transmitted and in which the pair of transmission line conductors extends parallel so as to have a first width, and a band rejection filter region in which the pair of transmission line conductors planarly overlaps the conductive film and extends parallel so as to have a second width narrower than the first width and a common mode of the differential transmission signal is attenuated at one of the frequencies which are natural number multiples of a frequency corresponding to the predetermined bit rate.

Abstract: An electromagnetic bandgap (EBG) pattern structure includes a nonconductive substrate and a pattern assembly formed on the substrate. The EBG pattern structure also includes regularly arranged closed-loop patterns and open-loop patterns, both of which are made of a conductive material. The EBG pattern structure can be used to manufacture new security products by applying its frequency characteristics to securities or IDs and variously used in security technologies for preventing forgery and alteration because various security codes can be created by adjusting the variables of its EBG pattern.

Abstract: A differential filtering device with coupled resonators, including: a pair of coupled resonators disposed on one and the same face of a dielectric substrate, each resonator including two conducting strips positioned in a symmetric manner with respect to a plane perpendicular to the face on which the resonator is disposed, these two conducting strips being joined respectively to two conductors of a bi-strip port for connection to a line for transmitting a differential signal, wherein each conducting strip of each resonator is folded back on itself so as to form a capacitive coupling between its two ends, and wherein the two resonators of the pair are coupled by the disposition opposite one another of their respective conducting strips disposed on the same side with respect to the symmetry plane, over respective portions of length of these folded-back conducting strips.

Abstract: A signal transmission device includes: a first substrate and a second substrate; a first resonance section including a first resonator and a second resonator electromagnetically coupled to each other; a second resonance section disposed side-by-side relative to the first resonance section, and electromagnetically coupled to the first resonance section to perform a signal transmission between the first and second resonance sections; and a first shielding electrode disposed between the first resonator and the second substrate and partially covering the first resonator to allow at least an open end of the first resonator to be covered therewith, and a second shielding electrode disposed between the second resonator and the first substrate and partially covering the second resonator to allow at least an open end of the second resonator to be covered therewith.

Abstract: Microstrip filters and methods of operation are described. In one aspect, a filter includes a substrate having a substantially planar surface and a microstrip patch located on the surface of the substrate. The microstrip patch includes multiple symmetric slots in the microstrip patch, a first feed line extending from the microstrip patch, and a second feed line extending from the microstrip patch. The first and second feed lines are asymmetric.

Abstract: A communication module includes a filter element, a package substrate on which the filter element is mounted, and a module substrate on which the package substrate is mounted. Each of the package substrate and the module substrate is formed of a laminate of a plurality of metal layers and a plurality of insulation layers. An outermost insulation layer forming a mounting surface of the package substrate that is a surface on which the filter element is mounted has a thickness smaller than a thickness of at least one of the other insulation layers included in the package substrate. An outer insulation layer forming a mounting surface of the module substrate that is a surface on which the package substrate is mounted has a thickness smaller than a thickness of at least one of the other insulation layers included in the module substrate.

Abstract: A band-pass filter according to the present invention includes two or more resonant lines arranged side by side in a direction orthogonal to a laminating direction in a laminate substrate formed by laminating plural dielectric layers. Each of the resonant lines has a first coil pattern portion formed in the dielectric layers and a second coil pattern portion formed in the dielectric layers different from the dielectric layers in which the first coil pattern portion is formed. The first and second coil pattern portions are connected in series and formed in a spiral shape. At least one of the first and second coil pattern portions is formed as parallel lines in the plural dielectric layers. According to such a configuration, a band-pass filter that is reduced in size and reduced in loss is provided.

Abstract: A metamaterial includes a dielectric substrate and an array of discrete resonators at the dielectric substrate, wherein each of the discrete resonators has a shape that is independently selected from: an F-type shape; an E-type shape; or a y-type shape. A parameter of a chiral metamaterial is determined and a chiral metamaterial having such a parameter is prepared by the use of a model of the chiral metamaterial. The metamaterial model includes an array of discrete resonators. In one embodiment, each of the discrete resonators has a shape that is independently selected from the group consisting of: an F-type shape; an E-type shape; and a y-type shape. To the metamaterial model, electromagnetic (EM) radiation, preferably plane-polarized EM radiation in a visible, ultraviolet or near-infrared region, having at least one wavelength that is larger than the largest dimension of at least resonator of the metamaterial model, is applied.

Abstract: A resonator having respective electrode planes of first and second internal electrodes disposed so as to be substantially parallel to a line of magnetic force of a magnetic field. In the resonator, respective electrode planes of first and second external electrodes are disposed so as to be substantially parallel to the line of magnetic force of the magnetic field in planes different from the electrode planes of the first and second internal electrodes.

Abstract: A microwave device of the slot-line type with a photonic band gap structure, including at least: a first substrate in a dielectric material having a first permittivity ?r1, a second substrate in a dielectric material having a second permittivity ?r2, and between the two substrates, a conductive layer in which at least one slot-line is engraved, with, on the face of the first and second substrates opposite the face in contact with the conductive layer, facing the slot-line, periodic metal patterns. A compact filtering structure is realized.

Abstract: A bandpass filter, and a radio communication module and device using the same are disclosed.

Abstract: Coupling between non-adjacent resonators and wave propagation through the waveguide structure in distributed EM filters are reduced by forming one or more holes in one or more of the resonators (planar or folded) and by passing a conductive structure through each hole normal to the resonator. The conductive structures (vertical vias or horizontal strips) are preferably grounded, either by direct connection or capacitive coupling to one or more ground planes or by creation of a virtual ground. The holes are spaced apart from the edges of the resonator so as to minimize any interference with the current and fields concentrated at the edges of each resonator. These conductive structures narrow the effective cavity width “aeff” for the waveguide as a whole and between non-adjacent resonators without affecting the cavity width “a” between adjacent resonators.

Abstract: A microstrip filter having a plurality of hairpin microstrip resonators each having two substantially rectangular legs connected at one end and generally configured in a “U” shape. The microstrip filter may comprise a first of the plural resonators operatively connected to a first feed point, a second of the plural resonators operatively connected to a second feed point, and a third of the plural resonators operatively connected between the first and second resonators where an end portion of one of the legs of one of the resonators is tapered so that a thickness of the one leg is greater at one end of the one leg than at another end of the one leg.

Abstract: A plurality of vias is disposed side by side on a multilayer board. A first via which is one of the vias disposed at one outer portion is electrically connected to a first outgoing line provided on the multilayer board. A second via at the other outer portion is electrically connected to a second outgoing line provided on the multilayer board. A plurality of the vias is connected to a first fixed potential layer (a ground layer, for example) of the multilayer board. At least one second fixed potential layer is provided, with a plurality of the vias through a clearance and having the same potential as that of the first fixed potential layer, as an inner layer of the multilayer board between the first and second outgoing lines and the fixed potential layer. Therefore, a BPF whose rate of occupied area is low is formed on the multilayer board without additional production processes.

Abstract: A band-pass filter includes an input portion inputting an electromagnetic signal, an output portion outputting the electromagnetic signal, a plurality of transmission portions electrically connecting the input portion and the output portion to transmit the electromagnetic signal therebetween, and a pair of coupling members each shaping the frequency of the band-pass filter. Each of the coupling members includes a first coupling portion electrically connecting two of the transmission portions and a second coupling portion electrically connecting the first coupling portion. The first coupling portion includes a pair of parallel coupling microstrip lines of the same size. The second coupling portion includes a pair of transmission lines of different sizes.

Abstract: A filter includes a circuit board, a low-pass filter circuit, and a high-pass filter circuit. The circuit board includes at least one metal layer, and a dielectric layer attached on the at least one metal layer. The low-pass filter circuit is defined in the metal layer, and includes a main line that has two parallel portions, and a modulating circuit serving as a capacitor connected to the main line of the low-pass filter circuit. The high-pass filter circuit defined in the metal layer includes a main line that has two parallel portions and is connected to the low-pass filter circuit, and a modulating circuit serving as a conductor connected to the main line of the high-pass filter circuit.

Abstract: The resonator includes first high-impedance wiring plate-like, arranged parallel to top-surface ground electrode; second high-impedance wiring plate-like, arranged so as to face first high-impedance wiring; first columnar conductor electrically connecting first high-impedance wiring to second high-impedance wiring; first low-impedance wiring arranged between first high-impedance wiring and second high-impedance wiring; second columnar conductor electrically connecting first high-impedance wiring to first low-impedance wiring; second low-impedance wiring arranged between first low-impedance wiring and second high-impedance wiring; and third columnar conductor electrically connecting second high-impedance wiring to second low-impedance wiring, to reduce the area size the resonator.

Abstract: A low-pass filter includes an input portion inputting an electromagnetic signal, an output portion outputting the electromagnetic signal, a high impedance transmission portion electrically connecting the input portion and the output portion to transmit the electromagnetic signal therebetween, and a pair of low impedance transmission members arranged on opposite sides of the high impedance transmission portion. Each of the low impedance transmission members electrically connects the input portion, the output portion, and the high impedance transmission portion, and includes a first low impedance transmission portion and a second low impedance transmission portion. A width of the first low impedance transmission portion is different from that of the second low impedance transmission portion.

Abstract: Provided is a printed circuit board configured to remove undesired signals generated in a transmission line, the signals having frequencies that are integral multiples of a basic frequency. Two 1/4 wavelength lines 5 and 6 each having a length that is 1/4 of a basic frequency corresponding to a data rate of coded digital signal are arranged at a signal wiring layer, which is one of surface layers of a substrate 8, along a transmission line 3 for transmitting the digital signal. One end 15a of the first 1/4 wavelength line 5 is opened, and another end 15b is grounded to a ground 7. Both ends 16a and 16b of the second 1/4 wavelength line 6 are opened.

Abstract: Tunable bandpass filters are provided. In one embodiment, the invention relates to a tunable bandpass filter including a dielectric substrate having a first surface opposite to a second surface, a conductive ground plane disposed on the first surface, a microstrip conductive trace pattern disposed on the second surface, the trace pattern defining a phase velocity compensation transmission line section including a series of spaced alternating T-shaped conductor portions, at least one varactor diode coupled to a first T-shaped conductor portion of the series of T-shaped conductor portions and to the conductive ground plane, and bias control circuitry coupled to the first T-shaped conductor portion, wherein the bias control circuitry is configured to control the at least one varactor diode.

Abstract: Filter design techniques and filters based on metamaterial structures including an extended composite left and right handed (E-CRLH) metamaterial unit cell.

Abstract: A low pass filter includes a signal transmission line, a first open stub, a second open stub, a first coupling line, and a second coupling line. The signal transmission line is connected between a first port and a second port, and operable to transmit RF signals from the first port to the second port. The signal transmission line defines a first side and a second side opposite to the first side. The first open stub and the second stub are disposed on the first side and perpendicularly connected to the signal transmission line. The second open stub and the first open stub co-define a T-shaped gap. The first coupling line is parallel to the signal transmission line and disposed in the T-shaped gap. The second coupling line is parallel to the signal transmission line and disposed on the second side of the signal transmission line.

Abstract: The mobile wireless communications device includes a printed circuit board (PCB), wireless transceiver circuitry carried by the PCB and operating on a plurality of frequency bands, at least one antenna, and a multi-bandpass transmission line coupling the wireless transceiver circuitry to the at least one antenna. The multi-bandpass transmission line includes an electrically conductive trace on a surface of the PCB defining a transmission line signal path, and an electrically conductive layer on an opposite surface of the PCB and defining a ground plane. The electrically conductive layer has at least one set of slot rings therein and defining a plurality of slot ring resonators being electromagnetically coupled to the transmission line signal path and operable at the plurality of frequency bands.

Abstract: A filter unit and a corresponding printed circuit board. The filter unit and the printed circuit board have been equipped with modified end portions being matched such that a number of filter units can be used on the printed circuit board without changing the printed circuit board.

Abstract: A transmission line type resonator has a low-loss characteristic and, in order to realize the low-loss characteristic, the transmission line type resonator includes a laminate body formed of a plurality of dielectric sheets, a transmission line of complex right hand left hand system disposed between the plurality of dielectric sheets, and an external connection terminal disposed at the end face of the transmission line type resonator and connected with the transmission line of complex right hand left hand system.

Abstract: A microwave filter is provided that includes a transmission line having a signal input port and a signal output port, a stub connected to the transmission line between the input port and the output port, and a spurline embedded in the stub. The microwave filter is configured to substantially attenuate a frequency while substantially passing at least one predetermined odd harmonic of the frequency.

Abstract: A bandpass filter passes a range of frequencies with low loss while suppressing frequencies above and below the passed range of frequencies. One or more spurlines is included into the existing structure of the bandpass filter so that a selected odd multiple of the passed frequency range is suppressed.

Abstract: One embodiment of a high-frequency filter includes a band-rejection filter including a plurality of reflection-type resonance elements and a filter circuit element provided between the reflection-type resonance elements, wherein an electrical length between the reflection-type resonance elements between which the filter circuit element is provided is an odd multiple of 90 degrees in a rejection band of the band-rejection filter.

Abstract: A multi-band whip antenna having a 30 MHz to 2 GHz bandwidth and an L-band dipole has its coverage extended up to 6 GHz by eliminating nulls and reducing VSWR problems that are cured through the utilization of a sleeve over the feedpoint of the L-band antenna. Chokes in the form of sleeves are provided at either end of the L-band dipole to shorten the L-band antenna for preventing reverse polarity currents at the L-band antenna feedpoint, with the antenna further including the use of double shielded meanderlines to provide improved performance between 410-512 MHz and in which a capacitance sleeve is added at the bottom of the L-band antenna to effectively elongate the antenna below the L-band to permit operation below 700 MHz.

Abstract: A strip line filter includes a substantially rectangular plate-like shaped dielectric substrate. A ground electrode is arranged on a bottom surface of the substrate. A first resonant line and a second resonant line face the ground electrode through the substrate. Input/output electrodes are connected to the corresponding resonant lines. The first resonant line includes a first top-surface line, a connection line, and a second top-surface line. The first top-surface line is arranged on the top surface of the substrate and extends so as to pass a portion adjacent to a portion, on the left side, of a third top-surface line. The connection line and the second top-surface line are branched from the first top-surface line and pass a portion adjacent to a portion, on the right side, of the third top-surface line.

Abstract: An electric field coupler includes a strip-like coil formed by bending a strip-like conductor which snakes along a plane perpendicular to a coupling direction in which electric field coupling occurs, such that coil axes are perpendicular to the coupling direction, the strip-like coil having an electrical length of one-half wavelength of a predetermined frequency of a radio-frequency signal and having a form in which the coil axes surround a central portion along the plane. The strip-like coil produces coupling by a longitudinal wave electric field which vibrates in the coupling direction at the central portion.

Abstract: A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

Abstract: A wideband high frequency bandpass filter uses a metamaterial transmission line composed of an open-circuit resonator and a short-circuit resonator to realize a bandpass filter at the band of 60 GHz. The bandpass filter has an ultra-wide passband resulting from the coupling of the two resonators in the resonant modes thereof. The ultra wide passband formed by resonance coupling includes a left-handed passband and a right-handed passband. The two passbands jointly provides a passband ranging from 57.4 GHz to 63.6 GHz and having a bandwidth of 6.2 GHz. The stopbands of the bandpass filter are respectively extended downward from 57.4 GHz to the DC current and extended upward from 63.6 GHz to 109.4 GHz. The bandpass filter of the present invention can be applied to wireless transmission at the band of 60 GHz.

Abstract: In a multilayer band-pass filter, each of first-stage to third-stage LC parallel resonators includes capacitor electrodes, via electrodes, and a line electrode. Jump-coupling capacitor electrodes face the capacitor electrodes of the first-stage and third-stage LC parallel resonators. The direction in which the inductor electrode extends from the capacitor electrodes of each of the first-stage and third-stage LC parallel resonators is opposite to the direction in which the inductor electrode extends from the capacitor electrodes of the second-stage LC parallel resonator.

Abstract: A resonant element is provided with a multilayer board, comprising a plurality of conductor layers isolated by a dielectric, a signal via conductor, penetrating through the multilayer board, and a plurality of ground vias, penetrating thought the multilayer board and disposed around the signal via conductor. The multilayer board comprises a first conductor layer, a second conductor layer, and a corrugated conductor layer disposed between the first and the second conductor layers. The corrugated conductor layer comprises a corrugated signal plate, connected to the signal via conductor, and a corrugated ground plate, connected to the plurality of ground vias, isolated from the corrugated signal plate by the dielectric.

Abstract: A serial resonance circuit is prepared. The serial resonance circuit is configured of a pair of resonance circuit is configured of a pair of resonance elements serially connected to each other at a midpoint therebetween and exhibiting resonance frequencies equal to each other. To both ends of the serial resonance circuit, phase shift circuits that shift phases so that the phases are reverse to each other are connected. A resonance output obtained from the serial resonance circuit when AC power is supplied between the midpoint and an input side of the phase shift circuit is obtained as an external output.

Abstract: The invention relates to a direct-current blocking circuit, and a hybrid circuit device, a transmitter, a receiver, a transmitter-receiver and a radar device that have the direct-current blocking circuit. A dielectric substrate (2) is provided with a conductor layer (3) disposed parallel with the dielectric substrate (2), first and second planar lines (4, 5) each containing a part of the conductor layer (3), and a waveguide (6) containing a part of the conductor layer (3). The first and second planar lines (4, 5) are located on one surface (2a) side of the dielectric substrate (2) with respect to the conductor layer (3), and the waveguide (6) is located on another surface (2b) side of the dielectric substrate (2). In a transmission direction (X) of electric signals, as to the waveguide (6), its one end overlaps with one end of the first planar line (4), and its another end overlaps with one end of the second planar line (5).

Abstract: An electronic circuit includes a first transmission line connected to a DC power source, a second transmission line having one end connected to the first transmission line at a connecting node, a narrow portion formed in the second transmission line and provided at a position that is away from a specific position by equal to or greater than ? wavelength of a signal, the specific position being away from the connecting node at a distance equal to ¼ wavelength, and a capacitor having one end connected to the other end of the second transmission line and the other end connected to a reference potential.

Abstract: A distributed constant circuit includes a plurality of insulator layers including a first insulator layer that contains a first transmission line formed into a rectangular ring of less than one turn, a second insulator layer that contains a second transmission line which is electrically connected to the first transmission line through an inter-layer connection conductor, and which is formed into a rectangular ring of less than one turn, and a third insulator layer containing a ground electrode. In the distributed constant circuit, a rectangular spiral circuit pattern including the first transmission line and the second transmission line is formed by laminating the plurality of insulator layers.

Abstract: To pass an ultrahigh speed differential signal and sufficiently attenuate a common mode signal on an ultrahigh speed differential transmission line. A pair of conductor lines 1A and 1B are formed on one side of a dielectric layer 3 in parallel to each other. A floating ground 5 is formed on the other side of the dielectric layer 3 so as to face the conductor lines 1A and 1B. The floating ground 5 is not connected to an external common ground 7 and is formed independently. A passive two terminal circuit CM1 composed of passive circuit elements is connected between a connection point 9 between the floating ground 5 and a common ground 7.

Abstract: According to an embodiment of the present invention, an electromagnetic bandgap structure can include: at least three conductive plates; a first stitching via, configured to electrically connect any one of the conductive plates to another conductive plate; and a second stitching via, configured to electrically connect the one conductive plate to yet another conductive plate. In the electromagnetic bandgap structure of the present invention, the first stitching via can electrically connect the one conductive plate to another conductive plate by allowing a part of the first stitching via to be connected through a planar surface above the one conductive plate, and the second stitching via can electrically connect the one conductive plate to yet another conductive plate by allowing a part of the second stitching via to be connected through a planar surface below the one conductive plate.

Abstract: A distributed constant type filter includes a substrate including a part made of a first dielectric material having a first relative dielectric constant and a different-material part made of a second dielectric material having a second relative dielectric constant different from the first relative dielectric constant. A filter pattern is formed on a top surface and a ground pattern is formed on a bottom surface of the substrate. Part of the filter pattern is formed on the different-material part.

Abstract: Disclosed herein are a coupling structure for a multi-layered chip filter capable of overcoming a limitation of an existing coupling by improving a coupling structure and a multi-layered chip filter with the structure. The coupling structure according to an exemplary embodiment of the present invention includes: at least two overlap portion patterns each overlapped with a pattern formed on a resonator layer stacked therewith to form at least two overlap areas spaced from each other; and a connecting portion pattern formed by connecting at least three linear lines having a predetermined length to each other to connect the at least two overlap portion patterns to each other.

Abstract: An electromagnetic bandgap structure and a printed circuit board are disclosed. In accordance with an embodiment of the present invention, the electromagnetic bandgap structure includes a mushroom type structure comprising a first metal plate and a via of which one end is connected to the first metal plate; a second metal plate connected to the other end of the via; a first metal layer being connected to the second metal layer through a metal line; a first dielectric layer, layer-built between the first metal layer and the first metal plate; a second dielectric layer, layer-built on the first metal plate and the first dielectric layer; and a second metal layer, layer-built on the second dielectric layer. With the present invention, it is possible to solve the aforementioned mixed signal problem by preventing the EM wave of a certain frequency range from being transferred.

Abstract: An electromagnetic bandgap structure and a printed circuit board that solve a mixed signal problem are disclosed. In accordance with embodiments of the present invention, the electromagnetic bandgap structure includes a first metal layer; a first dielectric layer, stacked in the first metal layer; a second metal layer, stacked in the first dielectric layer, and having a holed formed at a position of the second dielectric layer; a second dielectric layer, stacked in the second metal layer; a metal plate, stacked in the second dielectric layer; a first via, penetrating the hole formed in the second metal layer and connecting the first metal layer and the metal plate; a third dielectric layer, stacked in the metal plate and the second dielectric layer; a third metal layer, stacked in the third dielectric layer; and a second via, connecting the second metal layer to the third metal layer.

Abstract: In a wiring substrate, a wiring layer includes a pair of differential transmission lines. A conductive layer is provided on one side of the wiring layer. The conductive layer is grounded. An insulating layer is provided between the wiring layer and the conductive layer. The conductive layer includes a region, formed by an electrically continuous conductor, within a filter region. At least part of the conductor is turned around in the region. Seen from a stacking direction, the pair of differential transmission lines intersects with at least two strip portions disposed counter to each other because of the turning-around of the electrically continuous conductor.

Abstract: The present invention provides a resonator and a filter that reduce the resonator radiation loss so as to achieve a high Q value that is inherent to a low-loss material while maintaining high power handling capability. In this manner, both high power handling capability and a high Q value can be achieved at the same time. The resonator is a microstripline structure and includes a line structure formed with resonance lines in which current standing waves are generated in a resonant state in a line, and currents in each two adjacent lines flow in the opposite directions from each other, and a connection line that connects the resonance lines at the portions having in-phase voltages among the nodes of the current standing waves of the resonance lines in the resonant state. The filter includes resonators of the same type as the above resonator.

Abstract: A stripline filter having a substrate, a grounding electrode, principal-surface lines, side-surface lines, and common electrodes, and is mounted on a set substrate by soldering. The side-surface lines are disposed on a side surface of the substrate, and are wetted by solder during soldering. Each of the common electrodes is connected to a corresponding one of the principal-surface lines. The common electrodes are also connected to the grounding electrode via the side-surface lines.

Abstract: A multi band-pass filter includes a first resonator and a second resonator. The first resonator has a first frequency pass band and a second frequency pass band. Moreover, the second resonator is electromagnetically coupled to another end of the first resonator. The second resonator has a third frequency pass band and a fourth frequency pass band, wherein the third frequency pass band overlaps (or is congruous with) the first frequency pass band and the fourth frequency pass band overlaps the second frequency pass band.

Abstract: A signal transmission device includes: a first substrate and a second substrate disposed to oppose each other in a first direction; a first resonator including a plurality of first quarter wavelength resonators provided in a first region of the first substrate, and interdigitally coupled to one another in the first direction, and a single or the plurality of second quarter wavelength resonators provided in a region of the second substrate corresponding to the first region and interdigitally coupled to one another in the first direction; and a second resonator electromagnetically coupled to the first resonator, and performing a signal transmission between the second resonator and the first resonator. The first and the second quarter wavelength resonators located at positions nearest to one another in the first resonator, respectively have open ends which are disposed to oppose one another, and respectively have short-circuit ends which are disposed to oppose one another.