Abstract: A shield that can prevent the thickness of a dielectric filter from increasing without increasing the manufacturing cost of the dielectric filter is disclosed. The shield of the present invention is to be attached to a dielectric filter and has a first plate, a second plate elongated from the first end of the first plate in a predetermined direction, a third plate elongated from the second end of the first plate opposite to the first end in the predetermined direction, and a projecting part projecting from the first plate at a portion between the first and second ends of the first plate. Since the shield can be fixed to the dielectric filter by pinching the both side of the dielectric block and the projecting part can be in contact with the metallization of the dielectric filter, the total thickness of the dielectric filter does not increase even the shield is attached.

Abstract: A band-trap filter includes a main body, an outer electrode, inner electrodes, strip-shaped wires, a signal input, a signal output, and a circuit board. The main body is made of a dielectric material with the outer electrode coating top, bottom, right, left, and rear sides thereof. The inner electrodes are provided inside the main body. The signal input and output are provided on the top side of the main body to electrically connect to the inner electrodes via the strip-shaped wires on the front side of the main body. Another strip-shaped wire electrically connects portions of the outer electrode at the top and the bottom side of the main body. Due to inductance and capacitance effects, the band-trap filter provides functions of both low-pass and high-pass filters and good electromagnetic interference rejection effect.

Abstract: The invention provides a composite dielectric filter device that can easily improve the isolation characteristics between mutually adjacent filters, even when using a compact dielectric block to miniaturize the entire configuration of the device. The invention also provides a communication apparatus incorporating the filter device. In the filter device, inner conductor holes are arranged inside a single dielectric block, and an outer conductor is formed on outer faces of the dielectric block. Additionally, an outer-conductor-free portion is formed at the boundary between a transmission filter and a reception filter formed by the inner conductor holes.

Abstract: The present invention relates to a dielectric device that is suitable for miniaturization and height reduction and is surface-mountable. In a resonator unit Q1, a first hole 41 is provided to a dielectric substarate 1, extends from a surface 21 toward a surface 22 opposite thereto, opens in the surface 21, and has a first internal conductor 61 in the interior. A second hole 51 is provided to the dielectric substarate 1, opens in a surface 23 adjacent to the surface 21, extends from the surface 23 toward a surface 24 opposite thereto, and is connected with the first hole 41 in the interior of the dielectric substarate 1. The second hole 51 has a second internal conductor 81 in the interior, and the second internal conductor 81 is connected to the first internal conductor 61 in the interior of the dielectric substarate 1.

Abstract: A filter with an equivalent circuit that functions as well as physically larger filters without substantial drop off in performance.

Abstract: The invention provides a dielectric filter comprising a dielectric block having two through bores, an outer conductor covering an outer peripheral surface of the block and one end face of the block, an inner conductor covering an inner periphery of the block, and a pair of input and output electrodes formed on the surface of the block, the other end face of the block being in the form of an open end face having no conductor layer. The pair of input and output electrodes are opposed to each other on one plane, and a dielectric block exposing portion having no conductor layer thereon is formed between the two electrodes. The block is provided in the other end face thereof with one groove dividing the open end face, and an inner surface defining the groove is provided with a conductor layer joined to the outer conductor.

Abstract: The invention provides a dielectric resonator device comprising a coaxial dielectric resonator 2 which comprises a dielectric block 21 having a bore 22 extending therethrough, an outer conductor layer 24 formed on an outer peripheral surface of the dielectric block 21, an inner conductor layer 23 formed on the dielectric block 21 over an inner peripheral surface thereof defining the bore 22, a short-circuiting conductor layer 25 providing a short circuit between the outer conductor layer 24 and the inner conductor layer 23, and a separated conductor layer 3 formed on the outer peripheral surface of the dielectric block 21 and electrically separated from the outer conductor layer 24. The separated conductor layer 3 is connected to the ground by a switch SW, which varies the capacity of the resonator 2 upon switching to alter the resonance frequency thereof.

Abstract: The invention provides a dielectric filter device comprising a first electrode formed on a dielectric block for connection to an antenna, and a second electrode formed on an upper surface of the block for connection to a communications device, openings of hollow bores being arranged between the first and second electrodes to provide a filter for passing a predetermined frequency band, a plurality of hollow bores being arranged between the second electrode and a side surface of the block to provide traps having a plurality of attenuation poles. Attenuation of frequencies in the pass band can be diminished without providing an external circuit.

Abstract: A method of adjusting characteristics of a dielectric filter including the following steps: forming a dielectric filter having a dielectric body, the dielectric body having an outer surface; forming an external conductor on the outer surface of the dielectric body; and forming at least one hole extending through the dielectric body, the at least one hole having a respective inner surface, and a respective internal conductor and a respective non-conductive portion at the inner surface; the outer surface of the dielectric body comprising first and second end surfaces and a side surface extending between the first and second end surfaces; the at least one hole extending through the dielectric body between the first and second end surfaces; the respective inner conductor being formed as a respective pair of internal conductors conductively connected to the external conductor at respective ends of the at least one hole, the respective non-conductive portion at the inner surface of the at least one hole being space

Abstract: A duplexer/diplexer comprising at least a transmission branch and a reception branch. The transmission branch and the reception branch are modularly connected by shielding, and are arranged such that the two branches are matched to an identical value of resistance (50 Ohms) in their passband, and offer broadband high-impedance in the stopband of the band neighboring the passband. As a result, all three ports of the duplexer/diplexer are matched to the same value of resistance given parallel connection of the two branches.

Abstract: A dielectric filter and a dielectric duplexer, which obviate the need to change the design of a circuit board when the dielectric filter or the dielectric duplexer are to be changed and in which the degree of freedom of design is improved, and a communication apparatus using them are constructed. Resonator holes having internal conductor formed on the respective inner surfaces thereof, and excitation holes are provided in a dielectric block, and electrodes and an external conductor are formed on the outer surface of the dielectric block. The positions of input/output coupling electrodes on the mounting surface with respect to the circuit board are aligned with the positions of the input/output coupling electrodes on the circuit board. At least one of the electrodes provided on the opening surfaces of the resonator holes is disposed in a direction which is not perpendicular to the mounting surface.

Abstract: The present invention provides a dielectric resonator, a dielectric filter, a dielectric duplexer capable of reducing leakage of electromagnetic waves and capable of being miniaturized, and a communication apparatus incorporating the same. In each of the dielectric resonator and filter, inside a dielectric block, there is formed a L-shaped inner-conductor-formed hole having a bend at some point of the hole in a manner extending from an outer surface of the dielectric block to a surface perpendicular to the outer surface. An inner conductor is formed on the inner surface of the inner-conductor-formed hole. On the substantially entire outer surfaces of the dielectric block, there is disposed an outer conductor, with one end of the inner-conductor-formed hole open-circuited and the remaining end of the hole short-circuited. Around the edge of the open-circuited end there is formed an outer coupling electrode.

Abstract: The invention provides a dielectric filter device having first bore opening portions arranged between a first electrode formed on an upper surface or side surface of a dielectric block and a second electrode formed on the upper surface to provide a filter for passing a predetermined frequency band, and a second bore opening portion disposed between the second electrode and the side surface of the block. A conductive layer on the outer peripheral side surface close to the second electrode is removed in the form of a strip from at least one portion of the peripheral side surface which portion extends from the upper surface to the lower surface of the block. Unnecessary resonance in a high frequency range outside the pass band can be suppressed without providing an external circuit.

Abstract: The invention relates to a resonance trap (8) for suppressing electromagnetic coupling phenomena for a line (1), which resonance trap includes a conductor (10) which extends parallel to and along a part of the length of the line (1). Conventional resonance traps (8) have the drawback that a direct connection exists between the RF line and the individual resonance traps (8). It is an object of the invention to provide a resonance trap (8) which enables a modular assembly on the line (1). The object is achieved by means of a resonance trap (8) of the kind set forth in which inner conductors (10) extend parallel to the line (1) and in which outer conductors (11) extend parallel to the inner conductors (10), said inner conductors (10) being arranged at a radial distance from the line (1) which is smaller than that at which the outer conductors (11) are arranged and the outer conductors (11) being arranged to cover at least partly the inner conductors (10) in the radial direction relative to the line (1).

Abstract: The present invention is a filter and a method of making a filter to remove unwanted frequency harmonics associated with current filters. The filter is made up of resonators, such that the filter resonates a design frequency. Whereby, at least two resonators are coupled together between an input and an output and at least one of the resonators is of a different design from other resonators, such that the resonator of a different design resonates the same design frequency as the other resonators and resonates different higher order harmonic frequencies than the other resonators. The present invention also provides methods of improving skirt response for a filter, as well as other response properties of the filter. One way to improve the filter's properties is where at least one of the resonators in a filter is reversed in orientation as compared to the other resonators.

Abstract: In accordance with the invention, coupled transmission lines are fabricated in forms that are tolerant of manufacturing variation or can be readily tuned. In accordance with a first embodiment, the transmission line is formed with alternating overlapping edges for enhanced manufacturing tolerance. In a second embodiment, the line is provided one or more overlapping adjustment regions to permit tuning. A third embodiment has both alternating overlapping edges and one or more tuning regions.

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

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

Abstract: A dielectric duplexer includes a substantially rectangular dielectric block. The dielectric block includes inner-conductor-containing holes each having an inner conductor on the inner surfaces thereof, and inner-conductor-unformed portions on which the inner conductors are not formed are formed in the vicinity of first ends of the inner-conductor-containing holes. The dielectric block further includes an outer conductor and input/output electrodes which are formed on the outer surface thereof, and the input/output electrodes are separated from the outer conductor. A through-hole having a short circuited electrode formed on the inner surface thereof is provided between two of the inner-conductor-containing holes so as to run from the mounting surface to the surface opposite thereto.

Abstract: RF and microwave radiation directing or controlling components are provided that may be monolithic, that may be formed from a plurality of electrodeposition operations and/or from a plurality of deposited layers of material, that may include switches, inductors, antennae, transmission lines, filters, and/or other active or passive components. Components may include non-radiation-entry and non-radiation-exit channels that are useful in separating sacrificial materials from structural materials. Preferred formation processes use electrochemical fabrication techniques (e.g. including selective depositions, bulk depositions, etching operations and planarization operations) and post-deposition processes (e.g. selective etching operations and/or back filling operations).

Abstract: A coaxial capacitor is inserted in a coaxial cable in a predetermined position. A housing is provided as a ground conductor path in order to establish conduction between two external conductors in portions of the coaxial cable which are separated by the inserted coaxial capacitor. Inside the housing, a resonator formed by a dielectric coaxial resonator or the like, the coaxial capacitor, and a connecting conductor are accommodated.

Abstract: The present invention is a filter and a method of making a filter to remove unwanted frequency harmonics associated with current filters. The filter is made up of resonators, such that the filter resonates a design frequency. Whereby, at least two resonators are coupled together between an input and an output and at least one of the resonators is of a different design from other resonators, such that the resonator of a different design resonates the same design frequency as the other resonators and resonates different higher order harmonic frequencies than the other resonators. The present invention also provides methods of improving skirt response for a filter, as well as other response properties of the filter. One way to improve the filter's properties is where at least one of the resonators in a filter is reversed in orientation as compared to the other resonators.

Abstract: A duplexing filter 10 suitable for use in a mobile communication system. The filter 10 has a core of dielectric material 12 with several through holes 30 that define resonators 25. The core 12 has metallized surfaces 16, 18, 20, 22 and 24 except for the top surface 14. Several metallized resonator pads 60 surround each of the through holes 30 on the top surface 14. A metallized serpentine region 61, 62 extends from one or more of the resonator pads 60 toward a side surface 18 of the core 12. The metallized serpentine region 61, 62 causes attenuation of a third harmonic frequency.

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

Abstract: A stepped portion is formed inside the inner-conductor holes arranged between both side surfaces of a dielectric block. The axis at an open end of the holes is made to be different from the axis at a short-circuited surface. The open ends of the inner-conductor holes are formed so as to be close to corresponding input-output electrodes.

Abstract: A dielectric filter which has suitable attenuation characteristics and which readily exhibits desired characteristics. First, second and third inner-conductor holes having an inner conductor on each of the surfaces thereof are formed inside a dielectric block having an outer conductor on the outer surface thereof. First and second I/O electrodes extend from opposing side-surfaces to the undersurface of the dielectric block and are separated from the outer conductor. The side-surfaces are orthogonal to the direction in which the inner-conductor holes are arrayed in the dielectric block, and the undersurface is a mounting surface for facing a mounting board. The first I/O electrode extends from one of said side-surfaces near the first inner-conductor hole, to a position beyond a remote side of the second inner-conductor hole, that is, the side near the third inner-conductor hole.

Abstract: The invention provides a dielectric filter device having first bore opening portions arranged between a first electrode formed on an upper surface or side surface of a dielectric block and a second electrode formed on the upper surface to provide a filter for passing a predetermined frequency band, and a second bore opening portion disposed between the second electrode and the side surface of the block. A conductive layer on the outer peripheral side surface close to the second electrode is removed in the form of a strip from at least one portion of the peripheral side surface which portion extends from the upper surface to the lower surface of the block.

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: The present invention is a preferred monoblock ceramic bandpass duplexer filter. The preferred filter has at least three I/O pads. One of the pads is coupled to an antenna, another is connected to a transmission circuit and the last pad is connected to a receive circuit. The filter is comprised of two sections: a transmission section and a receive section. The transmission and receive sections include resonators disposed on respective sides of the antenna pad. A first alternative signal path is disposed adjacent the ends of the transmission resonators. A second alternative signal path is disposed adjacent to the ends of the receive resonators. Each alternative signal path couples adjacent and non-adjacent resonators. A further feature of the filter of the present invention includes a shunt zero resonator for the transmission section. To the contrary, the present invention allows the elimination of a shunt zero resonator for the receive section of the filter.

Abstract: The invention provides a dielectric filter device comprising a first electrode formed on a dielectric block for connection to an antenna, and a second electrode formed on an upper surface of the block for connection to a communications device, openings of hollow bores being arranged between the first and second electrodes to provide a filter for passing a predetermined frequency band, a plurality of hollow bores being arranged between the second electrode and a side surface of the block to provide traps having a plurality of attenuation poles. Attenuation of frequencies in the pass band can be diminished without providing an external circuit.

Abstract: A dielectric filter stopping a frequency signal at a lower frequency band than a pass band as a reference band with a higher attenuation ratio to perform adjustment of the attenuation ratio even the lower frequency area. The dielectric filter comprises a predetermined conductive pattern on the front surface on a dielectric block in which a plurality of resonant holes are provided, the dielectric block including back and side surfaces covered with a conductive material, each resonant hole being covered with the conductive material in the internal surface, the predetermined conductive pattern being separated at a predetermined distance from the end portions of the resonant holes, whereby the predetermined conductive pattern forms a coupling capacitance between the adjacent resonators and a cross coupling capacitance between the resonators not adjacent to control an electromagnetic coupling over the whole dielectric filter.

Abstract: In a dielectric filter, from the top surface to the bottom surface of a substantially rectangular dielectric block, inner-conductor holes are formed. On the inner surfaces of the inner-conductor holes, inner conductors are formed except where non-conductor portions are formed in proximity to one of the top and bottom surfaces, in which the apertures of the inner-conductor holes are formed. On the outer surface of the dielectric block, an outer conductor is formed substantially over the entire outer surface, and input and output electrodes isolated from the outer conductor are coupled with the non-conductor portions in the respective inner-conductor holes at the ends of the dielectric block in the direction of array of the inner-conductor holes.

Abstract: An electronic part such as a dielectric duplexer or filter is provided which comprises a dielectric ceramic block having a pair of opposite first and second side surfaces and an end surface meeting the first and second side surfaces nearly at right angles, an extension-electrode forming notch formed in the end surface so as to have an open end at the first side surface, a dummy electrode-forming notch formed in the end surface so as to have an open end at the second surface, the extension electrode-forming notch and the dummy electrode-forming notch corresponding in shape and position when observed in the direction in which the first and second side surfaces are opposed, an extension electrode formed in the extension electrode-forming notch, and a dummy electrode formed in the dummy electrode-forming notch. A method of forming an electrode of such an electronic part is also provided.

Abstract: A dielectric filter includes a plurality of resonators provided in a dielectric block in parallel to each other. Each resonator is formed through providing an inner conductor on a wall surface of a through-hole extending between first and second end surfaces of the block. An outer conductor is provided on end and side surfaces of the block except for the first end surface. The inner conductor and the outer conductor are connected together so that the second end surface serves as a short circuit end surface, and the first end surface serves as an open end surface. A pair of input-output terminals are provided on a side surface of the block so that the input-output terminals are located adjacent to the open end surface at respective positions corresponding to open ends of two of the resonators. Insulating sections on the side surface isolate corresponding input-output terminals from the outer conductor formed on the side surface of the block.

Abstract: The extent of input/output coupling of a dielectric electronic component such as a dielectric filter or a dielectric duplexer can be adjusted by a novel method. The dielectric filter 1 comprises excitation holes whose short-circuiting ends are provided with respective coupling-adjusting countersinks.

Abstract: A dielectric filter having two outside resonators, one middle resonator disposed between the two outside resonators, and a notch pattern is provided. An input pad and an output pad are formed within respective non-coated lateral areas of a lateral surface corresponding to the outside resonators, respectively. The notch pattern is formed within an expanded non-coated lateral area of the lateral surface coupled to one of the non-coated lateral areas of the lateral surface which corresponds to a third position of the lateral surface corresponding to the middle resonator and one of the outside resonators. The notch filter is extended along the lateral surface from the input pad or the output pad toward the middle position corresponding to the middle resonator. The notch filter forms an electrical capacitor between the middle resonator and the input pad or the output pad.

Abstract: A TEM mode &lgr;/4 dielectric resonator includes a rectangular dielectric block having a top planar surface, a bottom planar surface and four side surfaces, a first metal layer coated on the top planar surface, a second metal layer coated on the bottom planar surface, and a third metal layer coated on one of the four side surfaces.

Abstract: A dielectric filter includes a dielectric block having a plurality of outer surfaces including opposed top and bottom surfaces, opposed side surfaces and a mounting surface. A plurality of through holes extend between the opposed top and bottom surfaces. Respective internal electrodes are located on internal surfaces of the through holes and an outer conductor is formed on at least some of the outer surfaces. First input output electrode extends from the mounting surface to one of the side surfaces. A second input output electrode extends from the mounting surface to the other of the side surfaces. Each of the first and second input output electrodes are separated from the outer conductor by a respective conductor-free portion wherein at least one corner of an outer shape of each of the conductor-free portions is formed as a continuous line having no right angles.

Abstract: A reduced size ceramic block filter has trap holes whose center is askew from the line running through the center of the transmission poles such that the height-wise distance between its center and the center line of the transmission poles is approximately between {fraction (1/8 )}and {fraction (3/8 )}of the height of the filter. The trap hole is also width-wise spaced from the next nearest transmission hole by an amount which approximates the distance between transmission holes. Due to this layout the diameter of the trap holes are reduced in order to maintain performance which is equivalent to a conventional filter whose trap holes are timely aligned with its transmission poles. The combination of reduced trap hole diameter and reduced width-wise spacing between traps and transmission holes, results in a reduced size ceramic filter.

Abstract: A coupled filter section is formed with a two piece construction. The filter section includes a first portion formed as a first unitary piece which has relief areas therein which define a plurality of cavities, a corresponding plurality of resonators or resonator portions located within each of the of cavities, a plurality of channels allowing magnetic coupling between adjacent cavities, and a plurality of coupling stubs disposed within the channels. The second piece is affixed to the first portion to substantially enclose the relief areas of the first portion. Preferably, the second piece includes post sections which are coaxially aligned with the resonators. The coupled filter section can include coupled triplet and coupled quadruplet sections.

Abstract: The present matching circuit chip has an integrated shape comprising a first transmission line, a second transmission line and a third transmission line, wherein one end of the first transmission line, one end of the second transmission line and one end of the third transmission line are connected to one another, a first filter connection terminal is connected to the other end of the first transmission line, an antenna terminal is connected to the other end of the second transmission line, and a second filter connection terminal is connected to the other end of the third transmission line, whereby the second transmission line converts the characteristic impedances of the first and third transmission lines so that the impedance matching between the antenna terminal and the first filter connection terminal can be attained, and so that the impedance matching between the antenna terminal and the second filter connection terminal can be attained.

Abstract: A duplexing communication signal filter has a substantially U-shaped core of dielectric material including a transmit arm, a receive arm and a base portion joining the transmit arm to the receive arm. Both the transmit arm and the receive arm each define a series of through-hole resonators. Present on the core of dielectric material is a surface-layer pattern of metallized and unmetallized areas. The pattern includes a wide area of metallization for providing off-band signal absorption, a first unmetallized area surrounding a plurality of the through-hole openings of the transmit arm, a second contiguous unmetallized area surrounding a plurality of the through-hole openings of the receiver arm, a transmitter pad metallized area on the transmit arm, a receiver pad metallized area on the receive arm, and an antenna pad metallized area.

Abstract: A dielectric filter having a notch pattern includes a dielectric block, in which a ground face plated with conductive metal for all the rest portions excepting an upper face thereof and both side given portions of one side wall face connected to the upper face is formed and numerous patterns plated with the conductive metal are formed on the upper face as a non-conductive part, input electrode provided on one portion out of non-conductive portions and formed so that a signal from the outside may be inputted thereto, at least two resonators formed piercing through upper and lower faces of the dielectric block, a lower end part of which is short-circuited on a lower face as the ground face of the dielectric block, wherein two resonators are connected with each other through a pattern formed on the upper face of the dielectric block in order to resonate and wave-transfer a signal inputted through the input electrode, and output electrode provided in the rest one portion out of the non-conductive portions on one

Abstract: The present invention relates to a coaxial cavity resonator having walls delimiting cavity, and one resonator body having a conductive rod with a first end being in short circuit relation to a first wall of the cavity walls. the first end a cross-sectional area. The resonator further includes a first conductive supportive plate with a first side connected to the first end of each rod. The first side has a larger area than the cross-sectional area of the first end of the rod and a second side, opposite the first side, fo the supportive plate is electrically connected to the first wall. A retainer is provided in the first cavity wall to guide the supportive plate, and an attachment is provided to secure the first supportive plate to the retainer. The invention also relates to a filter and a use of a resonator component in a filter.

Abstract: A plurality of cylindrical inner conductor portions having different diameters are connected with each other to form an inner conductor. The inner conductor portions include high-impedance portions and low-impedance portions. The inner conductor is formed within an outer conductor with a nonuniform inner diameter.

Abstract: A dielectric duplexer contains a substantially-rectangular-parallelepiped-shaped dielectric block. The dielectric block includes plated through holes having inner conductors formed thereon. An outer conductor is formed on an exterior surface of the dielectric block. An input/output terminal is formed by an outer-conductorless portion separating the input/output terminal from the outer conductor of the plated through holes and is defined by an outer-conductorless portion extending from a short circuit face of the dielectric block to a mounting surface thereof. An antenna excitation hole is formed as a through-hole in the same axial direction as that of the plated through holes in the dielectric block. The antenna excitation hole contains an electrode which is coupled to the antenna terminal. Two electrodeless portions, each having a predetermined shape, are formed between open edges of two plated through holes and a top face of the dielectric block.

Abstract: A dielectric filter, a dielectric duplexer, a communication apparatus are capable of arbitrarily determining the coupling degree of an external coupling without changing the intensity between resonators and miniaturization. Resonator holes are aligned in a dielectric block with a step structure of a large-diameter portion extending in a thickness direction of a dielectric block and a small-diameter portion smaller than the large-diameter portion, and a predetermined pitch is set between the small-diameter portions of the resonator holes and excitation holes by decentering the central axis of the small-diameter portion from the central axis of the large-diameter portion, thereby deciding the intensity of the external coupling.

Abstract: A compact dielectric resonator device that permits reduction in size of a metal cover without deterioration of the filter characteristics of the device. In this dielectric resonator device, a plurality of dielectric coaxial resonators are mounted on a substrate. A metal cover is arranged in such a manner as to enclose substantially only the open faces of the dielectric coaxial resonators, where terminals electrically connected to inner conductors of the dielectric coaxial resonators are led out. In addition, protrusions of the metal cover are electrically connected to parts of the outer conductors of the dielectric resonators between the adjacent dielectric coaxial resonators.

Abstract: A signal separator and bandpass filter that use plates with posts. The signal separator uses two bandpass filters to separate two signals of different carrier frequencies from one another. The bandpass filters each have a transmission line with the metallic plates disposed along its length. The number of plates and the distances between adjacent plates determine the bandwidth and the rejection capability of the filter.

Abstract: A high-frequency dielectric ceramic compact is provided which has a relative dielectric constant (∈r) of about 20 or less and a Q value of about 20,000 or more at 1 GHz, in which the temperature coefficient (&tgr;f) can be optionally controlled at about 0 (ppm/° C.). When the compact of the dielectric ceramic compact is represented by the formula aBaO.bMeO.cSbO3/2, 0.476≦a≦0.513, 0.160≦b≦0.175, and 0.324≦c≦0.350. In addition, when the compact of the dielectric ceramic compact is represented by the formula dBaO.eMeO.fSbO3/2.gTiO2, 0.476≦d≦0.513, 0.100≦e≦0.175, 0.200≦f≦0.349, and 0<g≦0.200.