Abstract: An apparatus and method are presented for combining electrical signals. The apparatus includes a phase-shift distributed element with an input to accept a first signal and an output to supply the first signal with a phase-shift; and a filter with a first signal port connected to the phase-shift element output, a second signal port to accept a second signal, and a third signal port to supply combined and filtered first and second signals. The phase-shift element has a signal path with a predetermined length and the phase-shift element output supplies the first signal with a phase angle shift responsive to the length of the signal path. In one example, the phase-shift element is formed from monoblock and coaxial elements, either singly or in combination, and is a tank circuit resonator in the filter.

Abstract: A variable radio frequency band filter capable of varying the resonance frequency band comprises a housing having a support; a number of resonator rods arranged along the longitudinal direction of the housing; at least one tuning rod positioned on top of the resonator rods; a tuning support extending through the respective tuning rods along the longitudinal direction of the housing and adapted to slide on top of the respective resonator rods to vary the position of the tuning rods; and a frequency variation unit positioned on a lateral surface of the housing. The frequency variation unit being coupled to an end of the tuning support and adapted to vary the position of the tuning rods, as the tuning support is slid, according to the frequency band.

Abstract: A cross-coupled dielectric resonator circuit. Resonator circuits in accordance with the invention may be used to build low-loss compact filters, oscillators, and other circuits, particularly microwave circuits. The resonators are arranged relatively to each other within an enclosure in a very efficient and compact design that enhances adjustability and coupling between adjacent resonators and the cross-coupling of alternate resonators.

Abstract: A method and apparatus for making an inner conductor from a conductive body integrally forms a flange on one end of the conductive body. The flange is formed integral to the conductive body by flaring the end of the conductive body. The size and shape of the flange is selected to achieve a desired capacitance surface area for use in a resonator. A resonator housing that has a plurality of cavities can be provided with a plurality of conductive bodies that are inserted into holes located in a bottom wall of the resonator body and that protrude into the plurality of cavities. The resonator housing and conductive bodies are placed onto a flanging fixture to produce a flange on each conductive body of a desired size and shape to achieve a desired capacitance surface area. The plurality of conductive bodies can be simultaneously flanged and fastened to the base of the resonator housing.

Abstract: A compact combline resonator and filter. The annular radius of inductive posts are modulated along the length of the inductive post to establish a desired inductive value for a series inductive capacitive resonator. The filter has a waveguide channel with an input port and an output port. One or more of the inductive posts are located in the waveguide channel, the one or more inductive posts providing filter poles and coupling the input port to the output port, each inductive post being electrically connected at one post end to a wall of the waveguide channel and providing a capacitance gap between an other post end and an opposing wall of the waveguide channel to provide a series inductive capacitive resonator.

Abstract: A cross-coupled dielectric resonator circuit. Resonator circuits in accordance with the invention may be used to build low-loss compact filters, oscillators, and other circuits, particularly microwave circuits. The resonators are arranged relatively to each other within an enclosure in a very efficient and compact design that enhances adjustability and coupling between adjacent resonators and the cross-coupling of alternate resonators.

Abstract: A high-frequency circuit device serving as a resonator includes a substrate and an electrode film which is formed on the surface of the substrate and which includes a conductive film and a dielectric film. The conductive film is formed around the substrate such that both ends of the conductive film overlap each other when viewed in a predetermined cross-section of the substrate, and the dielectric film is inserted between both ends of the conductive film. Accordingly, a self-capacitance portion is formed at the overlapped portion of the conductive film, electric-field energy is accumulated therein, and magnetic-field energy is accumulated inside the substrate. With this step impedance structure, the entire high-frequency circuit device can be miniaturized.

Abstract: An improved radio frequency diplexer has resonators which are associated either with the transmission path or with the reception path, and at least two additional resonators are also provided. The at least two additionally provided resonators form an interconnection resonator pair which are strongly coupled to one another. Both the transmission path and the reception path are coupled to the second additional resonator, or both the transmission path and the reception path are coupled to the first additional resonator which is provided for inputting to/outputting from the common signal path.

Abstract: An arrangement for bypassing a low-noise amplifier (LNA), intended especially to be used in base stations of mobile networks. For the bypass, a receiver antenna filter (210) has a second output (OUT2) parallel with a first output (OUT1) connected to the LNA. The antenna filter is of the resonator type, and there is a conductive element for each of its outputs in the resonator cavity. Selection between the LNA out-put signal and signal coming direct from the antenna filter is made by a changeover switch (SW). The noise figure of the receiver front stage (220) will improve as the series switch on the signal path, which most degrades the noise figure, is removed between the filter and LNA, and isolation on the LNA bypass path increases.

Abstract: A cavity filter assembly is provided with at least one structural cavity wall comprising a circuit board. The circuit board may also contain other circuits and circuit elements such as trim capacitors, inductors, low noise amplifier circuits and power amplifiers that are part of the filter's function. Input and output coupling structures and connectors may also be provided on the circuit board. The circuit board may contain inter-stage coupling circuits, signal traces, and coupling pads/structures. Further embodiments are provided that incorporate test connectors and directional couplers on the circuit board. In yet other embodiments the filter's electrical characteristics are tunable with trim elements mounted on the circuit board, such as capacitors or inductors, in either mechanical or electrical manner. The filter's electrical characteristics may also be tunable with mechanical elements mounted through the circuit board.

Abstract: A resonant circuit includes a transmission line in parallel with a varactor diode. The varactor diode has a capacitance that is variable in response to an applied voltage, which allows for real time impedance matching, attenuation control, and/or compensation for tolerances of other components. The resonant circuit is used with a quarter wavelength transmission line to provide impedance transformation and matching between multiple ports. A high frequency switch provides low current consumption, improved impedance matching, relatively low insertion losses, and excellent isolation between ports.

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

Abstract: A bandpass filter for a radio-frequency signal comprises an input section for a signal to be filtered, an output section for the filtered signal and at least one resonator electromagnetically or directly coupled to input and output sections. The shape of the resonator has binary rotation symmetry and/or mirror symmetry with respect to a signal propagation direction and is adapted to be excited into an oscillation having the same type of symmetry by applying the signal to be filtered to the input section.

Abstract: An improved radio frequency diplexer is distinguished inter alia, for example, by the following features:

Abstract: A radio-filter of combline structure with a capacitor compensation circuit, having a transmission line filter with at least one pair of transmission lines arranged between input and output terminals for filtering the input signals through the input terminal to select signals of a given frequency band delivered to the output terminal, each of the transmission lines having a via-hole at each of its ends, a capacitor compensator of lumped element connected through one of the via-holes to one of the transmission lines for providing capacitance between the transmission line and ground, and a ground layer connected to the other via-hole not connected with the transmission line to ground the transmission line.

Abstract: The invention provides a method and apparatus for an adaptively predistortion filter which has a transfer function that satisfies performance criteria specified for at least one property of the filter. The transfer function is obtained by adaptively predistorting the transfer function poles to meet the performance criteria such that at least one of the poles is shifted by a unique amount.

Abstract: A dielectric duplexer includes a substantially-rectangular-parallelepiped-shaped dielectric block. The interior of the dielectric block includes inner-conductor-formed holes containing inner conductors. An outer conductor is formed on the substantial entirety of an exterior surface of the dielectric block. Input/output electrodes and antenna input/output electrodes are formed at predetermined positions. Thus, the dielectric block is provided with a band eliminate filter and a band pass filter. A C-L-C &pgr;/2 phase circuit in which C, L, and C are arranged in the shape of the letter &pgr; is provided between an antenna and the antenna input/output electrode of the band eliminate filter, and the antenna is connected to the antenna input/output electrode of the band pass filter.

Abstract: A method for attaching an additional object to a resonator body. The method includes the steps of (1) placing the additional object in a recess of a pushing part of an extrusion machine; (2) pressing the pushing part against a bloom of a resonator body; and (3) pulling the pushing part back from the resulting resonator body. The attaching of the additional object occurs in conjunction with the extrusion process.

Abstract: A printed circuit for processing radio frequency signals includes a substrate including substrate regions upon which the printed circuit can be placed. The circuit is a coupled line filter including a plurality of resonator elements. The plurality of resonator line elements are at least partially coupled to respective substrate regions that have substrate characteristics that are each independently customizable. The circuit further comprises at least one ground or ground plane (50) coupled to the substrate.

Abstract: A microwave filter having a temperature compensating element includes a housing wall structure, a filter lid, a resonator rod, a tuning screw and the temperature compensating element. The housing wall structure defines a cavity. The filter lid closes the cavity. The resonator rod is within the cavity. The tuning screw is adjustably mounted through the filter lid and has a portion that protrudes into the cavity and is coaxial with the resonator rod. The temperature compensating element is joined to the filter lid or the housing and forms a bimetallic composite with the filter lid or housing that deforms with a change in ambient temperature.

Abstract: The invention relates to a method for attaching an additional object to an object made by the process of extruding, especially a resonator body, and to the structure resulting from the application of the method. A recess is made in the pushing part (ES) of an extrusion machine, which recess is shaped like a portion of the surface of the additional object. The additional object (320), such as a portion of the inner conductor of a resonator, is inserted prior to extrusion in the said recess so that the said portion of the surface of the additional object rests tightly against the surface of the recess and the rest of the surface of the additional object remains free. In the extrusion stage, the pushing part with the additional object is pressed (F) against a bloom of a resonator body whereby the material (31c) of the bloom is pressed tight against the free surface of the additional object. When the pushing part is retracted the additional object remains attached to the body element thus formed.

Abstract: A sharp-cutoff VHF elliptic filter includes a folded signal path and internally coupled feedback in a conductive enclosure. Sized for the power requirements of commercial television broadcast transmission, the filter implements the elliptic filter equation through use of cavities, resonators, and couplers. The negative feedback required by the elliptic filter equation is implemented by folding the RF signal path and coupling the feedback energy through a gap in an internal septum to sum negatively with the signal in the main signal path. The elliptic filter can have an interdigital configuration, which puts successive resonators on opposite walls of the enclosure and couples the signal at half-wavelength spacing. The elliptic filter can alternatively have a comb line configuration, which places all resonators on one wall and employs full-wavelength spacing.

Abstract: The present invention concerns a multilayered filter having a body consisting of multiple lateral layers, and comprising filter elements of transmission line configuration arranged according to a predetermined topology. According to the invention the filter elements further comprise multiple resonators arranged in two or more lateral layers, at least two resonators per lateral layer. Further according to the invention the filter comprises one or more intermediate partial ground planes, each arranged laterally between two layers.

Abstract: An arrangement for bypassing a low-noise amplifier (LNA), intended especially to be used in base stations of mobile networks. For the bypass, a receiver antenna filter (210) has a second output (OUT2) parallel with a first output (OUT1) connected to the LNA. The antenna filter is of the resonator type, and there is a conductive element for each of its outputs in the resonator cavity. Selection between the LNA output signal and signal coming direct from the antenna filter is made by a changeover switch (SW). The noise figure of the receiver front stage (220) will improve as the series switch on the signal path, which most degrades the noise figure, is removed between the filter and LNA, and isolation on the LNA bypass path increases.

Abstract: A printed circuit for processing radio frequency signals includes a substrate including substrate regions upon which the printed circuit can be placed. The circuit is a coupled line filter including a plurality of resonator elements. The plurality of resonator line elements are at least partially coupled to respective substrate regions that have substrate characteristics that are each independently customizable. The circuit further comprises at least one ground or ground plane (50) coupled to the substrate.

Abstract: An iris-less combline filter and a method of providing the iris-less combline filter are disclosed. The filter includes a conductive housing, first and second resonators disposed in the housing, and at least one capacitive coupling element disposed between the first and second resonators, wherein there is no decoupling iris between the first and second resonators.

Abstract: A system for inductively cross coupling resonators. Two resonators are interconnected by a cross coupler with the two ends, each end having a hole. The holes secures each end of the cross coupler to one of the resonators. The use of a stamped piece as a cross coupler results in a repeatable placement between resonators that minimizes any variation in coupling between resonators due to human error during assembly. This repeatability reduces assembly time and assembly cost.

Abstract: A microwave filter having a temperature compensating element includes a housing wall structure, a filter lid, a resonator rod, a tuning screw and the temperature compensating element. The housing wall structure defines a cavity. The filter lid closes the cavity. The resonator rod is within the cavity. The tuning screw is adjustably mounted through the filter lid and has a portion that protrudes into the cavity and is coaxial with the resonator rod. The temperature compensating element is joined to the filter lid or the housing and forms a bimetallic composite with the filter lid or housing that deforms with a change in ambient temperature.

Abstract: A multi-channel multiplexer has a substantially square shape and includes an N×N matrix with a common resonator. A plurality of input/output ports are connected to a common input/output port via respective resonators of the N×N matrix and the common resonator. The multiplexer provides a compact size, with balanced insertion losses and simple configuration to minimize phase difference of inter-resonator transitions.

Abstract: Disclosed is a radio frequency filter of a combline structure including a frequency cut-off circuit for cutting off a specific frequency from a frequency band having a given frequency bandwidth. The frequency cut-off circuit includes an inductive transmission line extending from the output terminal by a length determined to provide an approximate inductance corresponding to a calculated value approximate to an inductance for obtaining the specific frequency, and a capacitive element coupled to the approximate inductance provided by the inductive transmission line, so that it has a capacitance for obtaining the specific frequency. The inductive transmission line is connected to the capacitive element through a via hole formed at an end of the transmission line opposite to the output terminal, from which the transmission line extends. The invention also proposes a method for implementing the radio frequency 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: A temperature-compensated rod resonator, comprising a housing (10) having electrically conducting walls, including at least one electrically conductive resonator rod (14) extending from a bottom wall (11) towards a top wall (13), a temperature-compensating plate (20) located adjacent to said top wall (13) and coupling means (150, 151) for transferring electromagnetic energy to and from the resonator. The plate (20) is adapted to change its geometrical configuration in response to temperature variations. The temperature-compensating plate is a bimetallic plate (20) having a larger diameter than the resonator rod (14). A central portion (21) of said bimetallic plate (20) is secured to the upper end of the resonator rod (14), whereby the bimetallic plate, in conjunction with the adjacent top wall (13) defines a capacitance, which has a dominating influence on the resonance frequency.

Abstract: The present invention relates to a single-piece center conductor (15) for a LC-filter, and a LC-filter comprising at least one such center conductor. The center conductor comprises a first end section (20) with axially form confining fixing means and a second end section with means for direct connection to connecting means of a connector. A general object of the present invention is to provide an improved apparatus for connecting a LC-filter with a connector in terms of intermodulation interference, contact area with the LC-filter, accurate fastening to the LC-filter, assembly time, manufacturing, storage costs and logistics costs.

Abstract: The invention comprises a high-frequency low-pass filter (200) The filter utilizes distributed capacitance and inductance elements (221-227) which are realized using a homogeneous and relatively rigid conductive part (220). The conductive part is located mainly air-insulated in an enclosed metal housing (210) which serves as a ground conductor for the signal. The housing comprises conductive partition walls (212-214) to prevent coupling between adjacent capacitive elements. The advantages of the construction include good power handling capacity, good breakdown characteristics, small losses and low manufacturing costs, among other things.

Abstract: The invention relates to a bandpass filter comprised of coaxial resonators. On the side of a resonator chain (200) which makes the filter there is provided an additional equalizing resonator (EQ1) which is coupled to a resonator (R3) in the chain. The resonance frequency of the equalizing resonator and the coupling with the rest of the filter are arranged so that attenuation increases at a point corresponding to an original attenuation minimum. Thereby it follows that attenuation variation in the whole pass band decreases. Response equalization can be further enhanced by providing a second equalizer (EQ2) affecting a band beside the first one. Using the structure according to the invention, a decrease of a certain magnitude in the pass band attenuation variation of a bandpass filter can be achieved with a smaller increase in the number of resonators than in known structures. Moreover, the production costs caused by the additional structure are relatively small.

Abstract: The invention relates to a high-pass filter realized in a conductive casing by means of mechanical structural elements, which filter is suitable for signal processing especially at microwave frequencies. In the casing (201, 202, 203) there are in series rigid conductive elements (2IN, 210, 220, 230, 2OUT) separated from each other. Between successive elements there is capacitance that can be adjusted within certain limits, if necessary. The insulating material between the elements is air or plastic, for example. At least some of the conductive elements involve a conductor (214, 224) less than half a wavelength long, short-circuited at the opposite end to the casing. This together with the casing connected to the signal ground provides a transmission line which, looking from the conductive element, is inductive at the operating frequencies.

Abstract: An adjustable coupler for adjusting coupling between resonant elements of a filter includes an adjustment mechanism rotatively mounted to a filter housing and an isolation element fixed to the adjustment mechanism and disposed within the filter housing. The adjustable coupler further includes a conductive element having ends proximate resonant element of the filter. When the adjustment element is rotated with respect to the housing, the proximity of the ends of the conductive element to the resonant elements changes, thereby altering the coupling between the resonant elements.

Abstract: A cross-coupled bandpass filter for a microwave electromagnetic signal which utilizes a housing which has formed therein a plurality of sequentially located resonator cavities with these cavities being interconnected by in-line couplers. A resonator is mounted within each cavity. A cross-coupler is disposed between a pair of the cavities that are not sequentially located. The cross-coupler takes the form of a printed circuit board upon which are mounted at least one manually movable screw access to which is permitted exteriorly of the cavities.

Abstract: A multi-channel multiplexer has a substantially square shape and includes an N×N matrix with a common resonator. A plurality of input/output ports are connected to a common input/output port via respective resonators of the N×N matrix and the common resonator. The multiplexer provides a compact size, with balanced insertion losses and simple configuration to minimize phase difference of inter-resonator transitions.

Abstract: A cavity filter assembly is provided with at least one structural cavity wall comprising a circuit board. The circuit board may also contain other circuits and circuit elements such as trim capacitors, inductors, low noise amplifier circuits and power amplifiers that are part of the filter's function. Input and output coupling structures and connectors may also be provided on the circuit board. The circuit board may contain inter-stage coupling circuits, signal traces, and coupling pads/structures. Further embodiments are provided that incorporate test connectors and directional couplers on the circuit board. In yet other embodiments the filter's electrical characteristics are tunable with trim elements mounted on the circuit board, such as capacitors or inductors, in either mechanical or electrical manner. The filter's electrical characteristics may also be tunable with mechanical elements mounted through the circuit board.

Abstract: A communication device in which the problem caused by separately providing an antenna and a filter directly connected thereto, and the problem caused by separately providing a balanced-to-unbalanced transformer, have been solved. A dielectric filter having a both-end opened &lgr;/2 resonator is constructed by providing inner-conductor forming holes in a dielectric block. An antenna is constructed by forming a radiation electrode and terminal electrodes on a dielectric block. By bonding the antenna and dielectric filter, an antenna device is achieved which has a balanced feed antenna and which performs the input-output of unbalanced signals.

Abstract: The invention comprises a filter consisting of resonators (330, 320, . . . ) with a conducting housing, particularly to be used in networks operating on microwave frequencies. The couplings between the resonators are realised outside the conducting filter housing with the aid of a printed board (310) over a wall (306) of the housing. For a particular coupling a conductor strip (311) extending from one resonator to another is formed on the printed board, and openings (335, . . . ) are made in the resonator walls at the ends of the strips. In order to strengthen the coupling a coupling element (343) extending into the resonator cavity can be fastened as an extension of the strip. The filter connectors (301, . . . ) are also fastened to the printed board. The open filter housing (305) and the inner conductors (331, 341, . . . ) or the resonators can be made as a homogenous body. The manufacturing costs and the tuning costs of a filter according to the invention are relatively low.

Abstract: The invention relates to a high-pass filter realized in a conductive casing by means of mechanical structural elements, which filter is suitable for signal processing especially at microwave frequencies. In the casing (201, 202, 203) there are in series rigid conductive elements (2IN, 210, 220, 230, 2OUT) separated from each other. Between successive elements there is capacitance that can be adjusted within certain limits, if necessary. The insulating material between the elements is air or plastic, for example. At least some of the conductive elements involve a conductor (214, 224) less than half a wavelength long, short-circuited at the opposite end to the casing. This together with the casing connected to the signal ground provides a transmission line which, looking from the conductive element, is inductive at the operating frequencies.

Abstract: A radio frequency mechanical filter (10) of the resonant type employs a plurality of parallel spaced-apart resonators (40) disposed within a housing (16) defining a cavity. The resonators are supported at their first ends (46) to one wall (20) of the housing (16), with the remaining ends of the resonators being unsupported. A TEFLON support bracket (12) is disposed across the resonators (40) at points between the ends (44, 46) of the resonators. In one form, the support bracket (12) is movable along the length of the resonators to change the center frequency and bandwidth response of the filter.

Abstract: The invention relates to a method for attaching an additional object to an object made by the process of extruding, especially a resonator body, and to the structure resulting from the application of the method. A recess is made in the pushing part (ES) of an extrusion machine, which recess is shaped like a portion of the surface of the additional object. The additional object (320), such as a portion of the inner conductor of a resonator, is inserted prior to extrusion in the said recess so that the said portion of the surface of the additional object rests tightly against the surface of the recess and the rest of the surface of the additional object remains free. In the extrusion stage, the pushing part with the additional object is pressed (F) against a bloom of a resonator body whereby the material (31c) of the bloom is pressed tight against the free surface of the additional object. When the pushing part is retracted the additional object remains attached to the body element thus formed.

Abstract: In a sleeve in a radio frequency filter at least one portion having a lateral dimension being smaller than the diameter of a screw to be threaded through the sleeve is provided. The portion is flexible in a radial direction, so that a screw threaded through the sleeve will be secured by a clamping force. The increased friction provided by this clamping force will hold the screw in a locked position. The magnitude of the clamping force can be varied within broad ranges, and the optimum force will be different for different applications. Thus, by using such a screw and sleeve, there is no need for a lock nut and the screw does not need to be readjusted once placed in the correct position.

Abstract: The present invention relates to a cavity filter (20) that includes a plurality of centre conductors which are mounted on an elevation (22) that extends along several cavities. The elevation can be produced on the bottom surface (23) of the cavity body (21) to a high degree of flatness in one single working step, and a precise measurement and precise parallelity between said bottom surface and the side walls (25) of the cavities can be obtained.

Abstract: A bandpass filter is capable of forming attenuation extremes on both sides of a passband. Multiple microstrip line resonators, one end of each being an open terminal and the other end connecting to a ground electrode, are provided in a row, and the inner microstrip line resonators are bent in a C-shape so that the open terminals of the outer microstrip line resonators project further than the inner microstrip line resonators. The line of sight between the open terminals of the microstrip line resonators is improved and capacitance is formed there, so that attenuation extremes can be formed on both sides of the passband, and the amount of attenuation can be increased.

Abstract: A planar bandpass filter that comprises a substrate having a ground plane on one side and a plurality of resonators on the other side. Each resonator includes an elongated inductive portion and a capacitive portion. The elongated inductive portions are coupled through the substrate at the end opposite of the capacitive portion to the ground plane. The planar bandpass filter also includes a first tap and a second tap. The first tap is connected to a first elongated portion to serve as an input to the bandpass filter. The second tap is connected to a last elongated portion to serve as an output to the bandpass filter.

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.