Abstract: The present invention relates to a cavity filter including: an RF signal connecting portion spaced apart, by a predetermined distance, from an outer member having an electrode pad provided on a surface thereof; and a terminal portion configured to electrically connect the electrode pad of the outer member and the RF signal connecting portion so as to absorb assembly tolerance existing at the predetermined distance and to prevent disconnection of the electric flow between the electrode pad and the RF signal connecting portion, wherein a part of the terminal portion, positioned between the electrode pad and the RF signal connecting portion, is elastically deformed to absorb assembly tolerance existing in a terminal insertion port. Therefore, the cavity filter can efficiently absorb assembly tolerance which occurs through assembly design, and prevent disconnection of an electric flow, thereby preventing degradation in performance of an antenna device.

Abstract: An improved high-frequency shielded housing is characterized by the following features, among others: multiple contact sections (K; KG; KD) are formed or provided arranged offset to one another between the housing cover (17) and the housing (3), galvanic separating sections (T; TG; TD) are formed or provided between the contact sections (KG; KD), the housing cover (17) and the housing (3) are galvanically separated in the regions of the galvanic separating sections, and screw connections (25) are provided in the contact sections (K; KG; KD), the housing cover (17) and the housing (3) being galvanically contacted in the regions of the screw connections.

Abstract: A rod-switched tunable resonator includes a housing defining a cavity, a first rod disposed within the cavity, a second rod disposed within the cavity, and a switch connected to the first rod and to the second rod to tune the resonator to one of a plurality of frequencies by connecting or disconnecting one or both of the first and second rods to the housing. A tunable filter may be fabricated using two or more such resonators. The rod-switched tunable resonator may be a combline resonator, coaxial resonator, waveguide resonator, or dielectric resonator.

Abstract: A frequency converting circuit including: an impedance network having a first pair of terminals and operable to provide a first signal in a frequency band centered at a first frequency f1; an output network having second and third pairs of terminals and configured to pass, between the second and third pairs of terminals, a second signal in a frequency band centered at a second frequency f2 different from f1; a pump circuit having a fourth pair of terminals and operative to provide, at the fourth pair of terminals, a third signal at a pump frequency fp, where fp?f1 and f2; and a frequency converter having a first port connected to the first terminals, a second port connected to the second terminals and a third port connected to the fourth terminals, the frequency converter being operative to cause the difference between f1 and f2 to be equal to fp.

Abstract: A cavity filter includes a slider, a driving device, and an adapter. The slider is used to slide relative to and couple with a plurality of resonators located in the cavity filter to adjust a resonating frequency of the cavity filter. The driving device is used to drive the slider slide relative to the plurality of resonators and includes a shaft having a free end. The adapter is installed between the slider and the driving device and rotateably connected to the free end of the shaft with a gap configured between the free end and the adapter.

Abstract: A cavity filter is disclosed, which comprises a cavity, a cover plate, and a connector inner conductor disposed within the cavity, wherein the connector inner conductor passes through the cover plate to be connected with an external circuit board, the connector inner conductor comprises a first inner conductor and a second inner conductor, the first inner conductor is connected with a signal transmission point on the external circuit board, the second inner conductor is connected with an internal signal transmission point inside the cavity, the first inner conductor and the second inner conductor have a gap therebetween and cooperate with each other to form a structural capacitor, and the internal signal transmission point is connected with the signal transmission point on the external circuit board via the structural capacitor. A power amplifying module and a signal transceiving device are also disclosed.

Abstract: A resonance tube, a method for manufacturing a resonance tube, and a cavity filter, which relate to the field of communications devices and can provide a temperature compensation effect of different degrees, reduce a production cost, and improve production efficiency. The resonance tube is manufactured using powder materials, and the powder materials include at least one of carbonyl iron powder and iron powder and at least one of carbonyl nickel powder and nickel powder, a mass percentage of the at least one of carbonyl iron powder and iron powder in the powder materials is 58-70%, and a mass percentage of the at least one of carbonyl nickel powder and nickel powder in the powder materials is 30-42%. The present invention may be used on a communications device, for example, a base station.

Abstract: A dielectric core tunable filter for microwave frequencies of 0.5-30 GHz. The filter includes a low loss machined dielectric having multiple channels a portion of which are terminated in micro-electromechanical variable capacitors to realize coupled resonators. The machined dielectric is metalized with a material, such as copper, silver, or gold, and then patterned to provide ring shaped recesses at the ends of preselected channels.

Abstract: A cavity filter includes a housing having a positioning portion, a cover on top of the housing which have a pair of first positioning holes, a sliding plate with movably support on the positioning portion and mounted between the positioning portion and the cover to be configured to adjust a resonating frequency of the cavity filter, and a tuning structure fixed on the cover and having a pair of first positioning poles. The sliding plate includes a plurality of elastic arms, each of which is made of insulated material and supported by the positioning portion. Each of the pair of first positioning poles extends through the corresponding first positioning holes to touch the corresponding one of the plurality of elastic arms of the sliding plate.

Abstract: A cavity filter includes a slider, a driving device, and an adapter. The slider is used to slide relative to and couple with a plurality of resonators located in the cavity filter to adjust a resonating frequency of the cavity filter. The driving device is used to drive the slider slide relative to the plurality of resonators and includes a shaft having a free end. The adapter is installed between the slider and the driving device and rotateably connected to the free end of the shaft with a gap configured between the free end and the adapter.

Abstract: An improved microwave cavity filter used in cellular communication systems such as base stations is disclosed. The cavity filter has a conductive housing forming a cavity therein and a hollow conductive resonator configured in the cavity with a folded hat shaped upper portion. A tuning screw extends from the top cover of the housing into the top folded hat portion of the hollow resonator to fine tune the resonator. The resonator also may preferably include two different diameter sections providing a first high impedance section with smaller diameter and a second lower impedance section with a larger diameter configured at an upper end of the resonator. This configuration provides a significantly smaller cavity height for a given power handling capability. The resonator is preferably of constant thickness allowing low cost stamping or other forming techniques to be used in forming the resonator.

Abstract: A cavity filter includes a unitarily formed piece, a cap, a cover, and a tuning adjustment screw. The unitarily formed piece includes a bottom plate portion, a resonator tube body portion formed on a center of the bottom plate portion, and a sidewall portion extending from the bottom plate portion surrounding the resonator tube body portion. The resonator tube body portion defines a resonating cavity therein. The cap is attached onto a distal end of the resonator tube body portion. The cap and the resonator tube body portion cooperatively forms a resonator tube. The cover is attached to the sidewall portion, and the cover includes a screw hole. The cover, the sidewall portion, and the bottom plate portion cooperatively forms a chamber. The tuning adjustment screw is extending through the cover, threadedly engaged in the screw hole and aligned with the resonator tube.

Abstract: A cavity filter includes a unitarily formed piece, a cap, a cover, and a tuning adjustment screw. The unitarily formed piece includes a bottom plate portion, a resonator tube body portion formed on a center of the bottom plate portion, and a sidewall portion extending from the bottom plate portion surrounding the resonator tube body portion. The resonator tube body portion defines a resonating cavity therein. The cap is attached onto a distal end of the resonator tube body portion. The cap and the resonator tube body portion cooperatively forms a resonator tube. The cover is attached to the sidewall portion, and the cover includes a screw hole. The cover, the sidewall portion, and the bottom plate portion cooperatively forms a chamber. The tuning adjustment screw is extending through the cover, threadedly engaged in the screw hole and aligned with the resonator tube.

Abstract: A fixation arrangement for a resonator of a cavity body includes a cavity body including a base, a resonator defining a cavity and comprising a bottom, a screw including sharply arc-shaped head and securing the resonator on the base of the cavity body, and a sticky element located between the screw head of the screw and the bottom of the resonator.

Abstract: A ZnO varistor powder can be obtained with high operating voltage and excellent current-voltage nonlinear resistance characteristics. In the ZnO varistor powder, the main ingredient is zinc oxide (ZnO); and at least bismuth (Bi), cobalt (Co), manganese (Mn), antimony (Sb), nickel (Ni), and aluminum (Al), calculated as Bi2O3, CO2O3, MnO, Sb2O3, NiO, and Al3+, are contained as accessory ingredients in amounts of 0.3 to 1.5 mol % Bi2O3, 0.3 to 2.0 mol % Co2O3, 0.3 to 3 mol % MnO, 0.5 to 4 mol % Sb2O3, 0.5 to 4 mol % NiO, and 0.0005 to 0.02 mol % Al3+. ZnO content is greater than or equal to 90 mol %; the bulk density is greater than or equal to 2.5 g/cc; the powder is a spherical powder in which the 50% particle diameter in the particle size distribution is 20 ?m to 120 ?m.

Abstract: A system for accurate automatic satellite acquisition by a portable satellite terminal. The system includes a software program that coordinates inputs from several measurement aids to control antenna position. These aids include a GPS receiver, antenna azimuth, elevation and polarization angle sensors, and the terminal's modem, DVB receiver and spectrum analyzer, which contains a beacon detector also serving as Receive Signal Strength Indicator (RSSI). For satellite recognition, the spectral analysis and RSSI function are complemented by the lock/unlock indications provided by the modem and the DVB receiver. Under the control of the software program, the modem, DVB receiver and spectrum analyzer, in conjunction with an extensive database of satellites and their signal characteristics, provide the means for reliable validation of final alignment.

Abstract: A phase cancellation circuit for a cavity filter including a sampler loop assembly arranged to receive an input signal, a variable loop assembly connected to the sampler loop assembly by a cable, wherein the variable loop assembly is arranged to transmit an output signal from cavity filter, wherein the sampler loop assembly samples a cancellation signal at an isolation frequency from the input signal and transmits the cancellation signal to the variable loop assembly via the cable, and, wherein the cable has a length equal to a multiple of a half-wavelength at the desired isolation frequency, wherein the cancellation signal undergoes a 180° phase shift by traveling through the cable, wherein the variable loop assembly combines the cancellation signal with the input signal to cancel the input signal at the isolation frequency due to the 180° phase shift for creating the output signal with a notch at the isolation frequency.

Abstract: A resonator is provided with a tuning element based on piezoelectricity. The piezoelectric basic element includes at least one piezoelectric layer and a metal layer. Such a basic element is first coated with a thin insulating layer and then with a good conductor. The thickness of the conductive coating is greater than the skin depth of a field corresponding to the operating frequency of the structure in the conductor. The tuning element formed in this manner is fastened on, e.g., some inner surface of the resonator cavity and acts to change the natural frequency of the resonator by electric control. When using the tuning element, no mechanical arrangement is required for moving the tuning element. Furthermore, the tuning element does not cause considerable dielectric losses nor intermodulation when being in a radiofrequency electromagnetic field, because the field cannot significantly penetrate through said conductive coating into the piezoelectric material.

Abstract: An embedded resonator sharpens the frequency characteristics of a coaxial low pass filter. The resonator introduces finite transmission zeros to the response of the low pass filter, thereby suppressing spurious modes occurring just above the operating frequency. Two parameters are used to tune the operation of the embedded resonator. The length of an insert into the filter's transmission line substantially controls the resonant frequency, and the gap width substantially controls the coupling of the embedded resonator to the low pass filter.

Abstract: The invention is related to cavity resonators, a method for producing a cavity resonator, and a band pass filter system comprising cavity resonators. A cavity resonator (100) according to the invention comprises a printed circuit-board (10); an upper electrically conductive cap (20) having a three-dimensional structure (21); and a lower electrically conductive cap (30) having a three-dimensional structure (31). The structures of the upper cap (20) and the lower cap (30) are identical and the two caps (20, 30) are mounted on opposite sides of the printed circuit-board (10).

Abstract: A cavity filter defines a cavity with an opening on a top portion thereof and includes a lid to cover the opening of the cavity. A plurality of resonators are secured on a bottom portion opposite to the top portion of the cavity. The lid includes a plurality of bases extending from the lid toward the plurality of the resonators, respectively. A plurality of threaded holes penetrating the lid and one of the bases faces to the plurality of resonators, respectively. Each threaded hole includes a stopper portion extending from an inner surface of the threaded hole inward to form a step defining a hole in communication with the threaded hole. Each threaded hole corresponds to a tuning post to adjust a resonating frequency of the cavity filter.

Abstract: A semiconductor device interconnecting unit configured to input/output a high-frequency signal having a millimeter wave band to/from a semiconductor device is provided. The semiconductor or device interconnecting unit includes a part of a band pass filter configured to pass therethrough the high-frequency signal having a millimeter wave band by using an LC resonance circuit, and a remainder of the band pass filter, wherein the part and the remainder are separated from each other. The part is provided inside the semiconductor device, and the remainder is provided outside the semiconductor device. The part and the remainder include capacitors having variable capacitors added thereto, respectively. A pass band for the high-frequency signal having a millimeter wave band is changed by changing capacitance values of the variable capacitors.

Abstract: An improved high frequency filter displays the following features: the high frequency filter displays transmission behavior with a coupling impedance resonance having at least one blocking point at a frequency, the blocking point at the frequency being adjustable by presetting and/or preselecting a defined capacitive and inductive coupling between two coaxial resonators, one immediately following the other on a signal path.

Abstract: A stable and reliable built-in cross-coupled dielectric filter with temperature-independent performances and improved rectangular degree and amplitude-frequency characteristic is disclosed. The built-in cross-coupled dielectric filter comprises at least three sequentially welded coaxial dielectric resonators. Mutually coupled capacitors or mutually coupled inductors are etched on the two adjacent lateral surfaces of the adjacent coaxial dielectric resonators, respectively, with an alternate setup. The input and output ports of the built-in cross-coupled dielectric filter are positioned at the two coaxial dielectric resonators at the head and tail, respectively. The present invention is particularly applicable to the high-frequency realm such as microwave.

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

Abstract: A high Q cavity resonator loaded with a metallic post and a ceramic disc, the resonator comprising an inner conductive post having a length less than a quarter wavelength. The resonance frequency of the resonator is tunable by changing a distance between a) an outer plate and b) a ceramic disc and an end cap where the ceramic disc is located between the outer plate and the end cap. The resonance frequency can be tuned when the outer plate, ceramic disc, and end cap are in contact with each other by varying a pressure between the contact surfaces of the ceramic disc, the end cap and the outer plate. Temperature compensation allows the resonator to hold a resonance frequency over a range of tunable frequencies despite changes in temperature, and can be achieved by selecting thermal coefficients of expansion of components holding or placing the ceramic disc and end cap relative to the outer plate.

Abstract: In order to permit electronic tuning of the frequency of a circuit including dielectric resonators, such as a dielectric resonator filter, tuning plates are employed adjacent the individual dielectric resonators. The tuning plates comprises two separate conductive portions and an electronically tunable element electrically coupled therebetween. The electronically tunable element can be any electronic component that will permit changing the capacitance between the two separate conductive portions of the tuning plates by altering the current or voltage supplied to the electronically tunable element. Such components include virtually any two or three terminal semiconductor device. However, preferable devices include varactor diodes and PIN diodes.

Abstract: A microwave filter and method for remotely tuning a microwave filter from one sub-band to another sub-band using metallic rings to adjust the capacitance or inductance of the resonator. In adjusting the capacitance, a plurality of metallic rings are disposed in the upper section or end of the resonator. Each ring has an RF switch that connects or disconnects each ring to ground, thereby varying the capacitance of the resonator. In adjusting the inductance, a plurality of metallic rings are disposed perpendicular to the magnetic field of the resonator. Each ring has an RF switch disposed within the electrical path of the ring that opens or closes the electrical path of each ring. By opening and closing each ring, the magnetic field of the resonator is altered, thereby varying the inductance of the resonator.

Abstract: A high Q RF cavity resonator loaded with a ceramic disc, the resonator comprising an inner conductive post having a length less than a quarter wavelength. The resonance frequency of the resonator is tunable by changing a distance between a) an outer plate and b) a ceramic disc and an end cap where the ceramic disc is located between the outer plate and the end cap. The resonance frequency can be tuned when the outer plate, ceramic disc, and end cap are in contact with each other by varying a pressure between the contact surfaces of the ceramic disc, the end cap and the outer plate. Temperature compensation allows the resonator to hold a resonance frequency despite changes in temperature, and can be achieved by selecting thermal coefficients of expansion of components holding or placing the ceramic disc and end cap relative to the outer plate.

Abstract: A method of manufacturing a dielectric filter comprises the steps of: forming a dielectric block; depositing a conductor on the side surfaces and the second surface of the dielectric block, and forming a plurality of resonators, forming input and output terminals on the side surface of the dielectric block, and forming conductive patterns on at least a part of the area of the first surface; and depositing a thermosetting resin on the first surface provided with the conductive patterns, and curing the thermosetting resin. The dielectric filter comprising the protection layer on an open surface prevents defects such as a short circuit generated in a trimming step. The interval between the patterns is reduced to less than 0.04 mm, advantageously facilitating miniaturization of the dielectric filter.

Abstract: A voltage-controlled tunable filter includes at least two cavity resonators electrically coupled to each other. A voltage tunable dielectric capacitor is positioned within each of the resonators. Connections are provided for applying a control voltage to the voltage tunable dielectric capacitors. An input is coupled to the one of the resonators, and an output is coupled to the other resonator.

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: A filter or multicoupler has at least one resonator which can be electronically tuned by a tuning device, has at least one tuning element such as a tuning capacitor, a switching element for selectively connecting the tuning element electronically to the resonator, and a control device for the switching element. The resonator is a coaxial quarter-wave resonator with a central component having free surface perpendicular to the central axis for mounting of tuning devices.

Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Abstract: A coupler for coupling RF electromagnetic energy into or out of a resonant cavity of the type which includes a control post.

Abstract: A multi-resonator filter, including a housing, at least one resonating element, at least one high dielectric constant element, at least one fine tuning screw located above the at least one resonating element and secured in a housing cover by a locking nut, housing screws to secure the housing cover to the housing. Where at least two resonating elements and at least two high dielectric constant elements are present, at least two slots are located in the at least two high dielectric constant elements to allow the easy installation and removal of at least one high dielectric coupling bridge used to increase the coupling between resonator sections, and at least one coupling probe.

Abstract: The invention relates to an air-insulated coaxial resonator, which is particularly suitable for a structural part in duplex filters. The resonator has an inner conductor (301) extended at one end, so that it forms extra capacitance with the cover (303) of the resonator and the upper part (302y) of the outer conductor. Because of the extra capacitance, a resonator of a certain frequency is shorter than a corresponding quarter-wave resonator. Because of this it is also mechanically stronger and is more stable in its properties. The extension of the inner conductor and the shortening of the construction also have a dissipation-reducing effect. The extension (304, 305, 306a, 306b) can also be used for tuning the resonator and for coupling to the adjacent circuit elements. In a construction according to the invention, a third harmonic of the basic frequency component does not occur, which is a remarkable advantage in the manufacture of filters.

Abstract: A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Abstract: A radio-frequency filter (400, 500, 600) comprises a base plate (401, 603) and an electrically conductive ground plane in connection with it, a predetermined number of inner conductors (403A-403G, 501, 502, 601) attached substantially perpendicularly to the base plate which have a first end and second end, and an electrically conductive casing (402, 503, 602) which is connected at one side to the base plate and substantially surrounds said inner conductors. A first end of each inner conductor is in contact with said ground plane and a second end is in contact with said electrically conductive casing so that the resonators comprising the inner conductors, ground plane and casing function as half-wave resonators.

Abstract: The invention relates to a filter and a frequency tuning element. The filter comprises a shell construction (2a to 2d) of conductive material with at least one section (14 to 16) and in the shell construction (2a to 2d) at least one resonator (17 to 19) of conductive material in said at least one section (14 to 16) for forming at least one resonance circuit (11 to 13). In the filter (1) the resonator (18) comprises as its extreme ends a base (18a) and a second end (18b), in said filter (1) the base (18a) of the resonator (18) being fastened to the shell construction (2a to 2d) and the second end (18b) of the resonator (18) being directed elsewhere towards the shell construction (2a to 2d) at a distance therefrom, the resonator (18) comprising a means (32) which directs its surface towards the shell construction (2a to 2d) and increases the cross-sectional area of the resonator to increase the capacitance between the resonator (18) and the shell construction (2a to 2d).

Abstract: The invention relates to a resonator filter comprising a housing structure (10), at least one resonator conductor (20) in the housing structure, and a regulating means (30) for regulating the frequency band of the resonator filter. The regulating means (30) is substantially transverse with respect to the propagation direction of the resonator conductor so that the regulating means (30) forms at least one turn around the resonator conductor (20) transversely to the propagation direction of the resonator conductor.

Abstract: A dielectric filter is disclosed in which an open area without being spread with a conductive material is formed on the rear face of a dielectric block with a conductive material spread thereon, thereby making it possible to improve the filtering characteristics of the filter and to miniaturize the filter. That is, coupling capacitances and coupling inductances are formed between resonance holes of the rear face of the dielectric block. Further, conductor patterns are formed on the front face of the dielectric block so that coupling capacitances are formed between the resonance holes of the front face, and that loading capacitances are provided to the respective resonance holes.

Abstract: A dielectric resonator 5 is electrically connected to an input terminal 1 through a coupling capacitor C1. A dielectric resonator 6 is electrically connected to an output terminal 2 through a coupling capacitor C3. The dielectric resonators 5 and 6 are electrically connected to each other through a coupling capacitor C2. A voltage control terminal 3 is electrically connected to the cathode of a variable-capacitance diode D1 and to one end of the coupling capacitor C1 through a choke coil L1. The anode of the variable-capacitance diode D1 is electrically connected to the dielectric resonator 6. That is, the variable-capacitance diode D1 comprises a path interconnecting at least two of said dielectric resonators in a filter 15.

Abstract: A method of adjusting characteristics of a dielectric filter having integral electromagnetic shielding, the dielectric filter comprises a dielectric body having an outer surface including first and second end surfaces and side surfaces extending between the first and second end surfaces; an external conductor disposed on the outer surface of the dielectric body and providing integral electromagnetic shielding of the dielectric filter; at least one hole extending through the dielectric body between the first and second end surfaces; a respective pair of internal conductors provided in the at least one hole and conductively connected to the external conductor at respective ends of the hole, a respective non-conductive portion in the hole being spaced from both ends and thereby separating the pair of internal conductors and defining a respective capacitance between the pair of internal conductors; and signal input and output electrodes provided on the outer surface of the dielectric body and electrically isolate

Abstract: A dielectric filter is formed by a plurality of resonator holes which are formed in a single dielectric block in such a manner that they extend in a direction between an open-circuited end surface and a short-circuited end surface of the dielectric block. The resonator holes are opened only at the short-circuited end surface. An inner conductor is formed on an inner surface of each of the resonator holes. An outer conductor is formed on an outer surface of the dielectric block. Capacitor electrodes respectively corresponding to the resonator holes are formed on the open-circuited end surface of the dielectric block. Input/output electrodes electrically connected to the capacitor electrodes are formed in such a manner that they extend on both the open-circuited end surface and a bottom surface of the dielectric block.

Abstract: A tuner circuit includes a first IF signal generating a first oscillation signal, a local oscillator circuit outputting a local oscillator signal, a mixing circuit mixing the first IF signal and the oscillation signal to generate a second IF signal, and a first substrate on which at least the local oscillator signal is formed. The local oscillator circuit includes an oscillation circuit and a coaxial resonator connected to the oscillation circuit for correcting the influence of change in oscillation frequency owing to moisture and secular change. The coaxial resonator includes an impedance variable trimmer portion for adjusting the oscillation frequency, a central conductor provided at a fixed position with respect to the first substrate, and an insulator for providing insulation between the impedance variable trimmer and the central conductor. The impedance variable trimmer portion and the central conductor are adhered to one another via the insulator after adjusting is completed.

Abstract: A dielectric filter is made of a dielectric material and includes a molded member of a pillar shape which has a hole formed from the top surface thereof toward the inside, an inner electrode formed so as to cover the inner circumferential surface of the hole; an outer electrode provided so as to cover the outer surface of the molded member except a prescribed region, and a coupling electrode provided at least in a portion of the prescribed region. An electrode area of a region of the inner electrode which faces against the coupling electrode is adjusted, thereby adjusting the coupling capacitance which is formed between the inner electrode and the coupling electrode.

Abstract: In a dielectric resonator, through holes are formed between opposing two surfaces of a dielectric block, an outer conductor is provided on an outer peripheral surface of the dielectric block, and a plurality of inner conductors are formed on the inner surfaces of the through holes, isolated by non-conducting portions where the inner conductor is not provided. Near the open end of the inner conductor of the resonator hole, a non-conducting portion is formed by partially removing the inner conductor in the axial direction, at a position opposing to an adjacent through hole, or a position near the outer conductor, so as to increase odd mode or even mode characteristic impedance near the open end, whereby inductive coupling is adjustable.

Abstract: A stepwise regulated filter includes a resonator structure and a coupling connected to the resonator structure. The resonating frequency of a transmission line (HX1) acting as a resonator may be switched between at least three values. The switching is implemented using coupling elements (SL1, SL4) which are in an electromagnetic coupling (M2, M3) with the resonator (HX1). The potentials of the coupling elements (SL1, SL4) are affected by PIN diodes (D1, D2) acting as switches. A RF power signal, which is coupled from the resonator (HX1) to the coupling elements (SL1, SL4), is applied to both terminals of at least one diode (D1) with the same phase and power. Then the voltage across the diode (D1) cannot, in the blocking state, rise to a level that would cause undesirable mixing results or would damage the diode (D1).

Abstract: The invention relates to a coaxial resonator comprising an inner conductor (12) with walls defining therebetween a free space (24), and a housing portion (13) surrounding the inner conductor (12) and forming an outer conductor of the resonator. In order that connection to the inner conductor could be made very simply, the inner conductor (12) is made of sheet material in which slits (21; 33) extending in the direction of the inner conductor are made so that they form between them a tongue-like connecting part (22; 34) having its free end connected to a printed circuit board (11).