Abstract: A resonator or a filter consisting of resonators comprises an inner conductor or conductors and an outer conductor enclosing the inner conductor or conductors. It comprises a first part (201, 301, 401, 604, 701) and a second part (202, 302, 420, 501, 605, 702), of which the first part comprises at least a part of the inner conductor or conductors (203, 303, 402, 404, 703, 704, 705, 706, 707) and a part of the outer conductor (204, 205, 304, 305, 405, 406, 407, 408, 409), which is integral with the inner conductor parts and made of the same material, and of which the second part comprises such a part of the outer conductor (206, 207, 304, 305, 421, 422, 423, 424, 425) which, when connected to the first part, forms a continuous outer conductor enclosing the inner conductor.

Abstract: A dielectric device for high frequency application with a reduced loss of a high frequency component has at least a first dielectric on which a conductor is disposed and a second dielectric laminated on this dielectric and an additional dielectric with a dielectric constant lower than those of the first and second disposed in the vicinity of the side edge of the conductor.

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: A method and apparatus for implementing a delay line filter with a single cross-coupled pair of filter elements. In a first exemplary embodiment of the present invention, the filter is comprised of a plurality of symmetrically configured filter elements, wherein only two of the filter elements are cross-coupled. In a second exemplary embodiment of the present invention, the filter is comprised of a plurality of filter elements, wherein a first element is coupled to a second element, and the first and second elements are each coupled to at least two other elements and at least one of the at least two other elements for each of the first and second elements are the same.

Abstract: In a quarter-wave coaxial cavity resonator, having a cavity with a cylinder inner wall (1), and bottom (3) and top (4) walls and a symmetry axis (2) with a resonator bar (5), a high coupling degree to a feed line (12) is obtained by a T-formed antenna with two equally long arms forming the antenna proper and the stem (9) forming the lead to the feed line. The antenna proper has one end (10) electrically and mechanically connected to the bottom end (6) of the resonator rod, whereas the opposite end (11) is free, and the antenna is parallel to the resonator rod and at a small distance therefrom.

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: A trimming arrangement in a device for tuning and/or adaptation of electromagnetic waves includes at least one trimming screw galvanically connected to the device and at least one bushing portion arranged for inserting and securing the screw. The bushing portion includes a substantially pervious opening arranged in a part of the device, a section arranged in the opening reception of the screw and a constriction arranged in an axial direction of the opening, which constriction is provided to firmly but detachably secure the screw.

Abstract: A multilayer dielectric evanescent mode waveguide bandpass filter with resonators utilizing via hole technology is capable of achieving very narrow bandwidths with minimal insertion loss and high selectivity at microwave frequencies is provided. A typical implementation of this filter is fabricated with soft substrate multilayer dielectrics with high dielectric constant ceramics. This filter typically takes up less space than other filters presently available. A typical implementation operates at a center frequency of 1 GHz, although other center frequencies, such as approximately 0.5 GHz to approximately 60 GHz, are achievable.

Abstract: A multilayer dielectric evanescent mode waveguide bandpass filter with resonators utilizing via hole technology is capable of achieving very narrow bandwidths with minimal insertion loss and high selectivity at microwave frequencies is provided. The resonators may also be used as feed posts. A typical implementation of this filter is fabricated with soft substrate multilayer dielectrics with high dielectric constant ceramics. This filter typically takes up less space than other filters presently available. A typical implementation operates at a center frequency of 1 GHz, although other center frequencies, such as approximately 0.5 GHz to approximately 60 GHz, are achievable. The perimeter of the filter may be defined by via holes or plated slots.

Abstract: A tubular assembly for use in an RF filter having an internal cavity. The tubular assembly includes a hollow tube and a flare positioned inside the hollow tube for mounting the hollow tube onto the filter housing. The flare includes at least two engagement surface portions which engage the inner wall of the hollow tube. During assembly, the flare engagement surface portions expand thereby locking the hollow tube on the filter housing.

Abstract: A coaxial resonator filter (1', 50, 50', 50") comprises a dielectric boardlike element (11, 51, 51") and on its surface at least one electrically conductive element (17, 19, 20, 21, 52) to provide an electromagnetic coupling to at least one coaxial resonator (3, 53). The dielectric boardlike element may be the same as the filter's base plate, in which case its outer surface comprises a continuous earth plane (55), or it may be parallel to a separate electrically conductive base plate (56). Link (17), tap (19) and capacitive (20) coupling elements can be realized on the surface of the dielectric board.

Abstract: A dielectric filter having a plurality of dielectric coaxial resonators provided on a dielectric ceramic block, which is capable of equalizing the resonance frequencies of all the dielectric coaxial resonators with ease, and a method for adjusting the resonance frequency of the dielectric filter, in which one or more counterbores is provided for adjusting the substantial resonance frequency of each of the dielectric coaxial resonators or for coping with a tendency toward any deviation of the resonance frequency based on the structure of the dielectric filter. Each counterbore has a diameter larger than that of an inner conductor of each of the dielectric coaxial resonators.

Abstract: The present invention relates to an integrated radio unit used in radio base stations in mobile telephony. One housing is provided for all elements of an integrated radio unit, including a functional unit and a center conductor plate. The combination of the cover and base of the housing form protective cavities for the functional unit and, simultaneously, a cavity whose shape, in combination with the center conductor plate, helps form the filter characteristics of the integrated radio unit. The design of the housing reduces the need for extensive connections between elements and also provides a cavity which, in combination with the center conductor plate, will act as a filter.

Abstract: A partially interdigitated combline ceramic filter is provided. The filter has a filter body with top, bottom, and side surfaces, and metallized through-holes defining quarter-wavelength resonators. The filter also has a metallization layer and at least one combline section with at least one transmission zero between the quarter-wavelength resonators. The filter also has at least one interdigital section and a coupling means between the quarter-wavelength resonators of the interdigital section. The filter also has first and second input-output pads. The partially interdigitated combline ceramic filter has the best attributes of both interdigital filter designs and combline filter designs to provide a filter which has transmission zeros, superior stopband rejection, and good harmonic performance in a small, compact, low-profile package that does not require external shielding.

Abstract: The invention relates to a filter and a method for manufacturing a filter. The filter comprises a shell construction with a wall construction and a bottom portion, which form at least one section in the shell construction. The filter further comprises at least one resonator within a section of the shell construction. At least the bottom portion of the shell construction and one or more resonators, or at least the part thereof close to the bottom portion of the shell construction, are an integral unit extruded from the same basic block in one piece.

Abstract: A line width on the grounded side of distributed-constant-line-type resonators which form a distributed-constant-line-type filter is made wider than a line width on the open side. By increasing the line width on the grounded side, where a larger electric current flows, of a distributed-constant-line-type resonator, the line resistance of the distributed-constant line decreases, making it possible to reduce the loss of the distributed-constant-line-type resonator and further to reduce the insertion loss of the distributed-constant-line-type filter. Further, by decreasing the line width on the open side to less than the line width on the grounded side, an increase in the size of the filter because the line width on the grounded side is increased can be prevented.

Abstract: A multi-passband filter includes a dielectric member (1), a plurality of resonant lines (12a-12c,13,14a-14d,15a-15c) provided within or on the dielectric member (1) and the resonant lines (12a-12c,13,14a-14d,15a-15c) are coupled to adjacent resonant lines so that a plurality of resonators are provided. At least one pair of resonant lines (12a-12c,13,14a-14d,15a-15c) are interdigitally coupled to each other in such a manner that the open ends and short-circuited ends of said resonant lines (12a-12c,13,14a-14d,15a-15c) are located in opposite directions with respect to each other, thereby providing a band-elimination filter. At least one pair of said resonant lines (14a-14d) may be comb-line coupled to each other in such a manner that the open ends and short-circuited ends of said resonant lines (14a-14d) are located in the same direction with respect to each other, thereby providing a band-pass filter. The multi-passband filter requires only a limited space to dispose the band-elimination filter in the filter.

Abstract: A duplexer, usable to interlink a receiver unit, transmitter unit, and an antenna unit of a communication system, has a body that includes cavities and interconnecting apertures. The duplexer further includes resonator covers that cover the cavities and apertures from a bottom side of the body and tuning covers that cover the cavities and apertures from a top side of the body. The resonator covers have integral resonator posts that extend into the cavities when the resonator covers are press-fitted into the body. The tuning covers have threaded openings for the insertion of tuning screws into the cavities and for the insertion of coupling screws into the apertures. The cavities and apertures are tuned to reflect or pass signals of selected frequencies by turning the tuning screws and coupling screws.

Abstract: A dielectric filter comprises transmission paths each of which is coupled to an associated input/output conductor provided in a dielectric ceramic block, and may be operated as capacitance means or inductance means, in which an intended center frequency can be obtained by suitably setting the lengths of the transmission paths without changing the length of each resonance conductor.A method of adjusting the center frequency of a dielectric filter in which the center frequency of the dielectric filter is adjusted to a desired value by changing the length of each transmission path located on the top surface having a relatively wide area of the dielectric ceramic block, which may behave as capacitance means or inductance means, and the adjusting operation becomes easy and production costs can be reduced.

Abstract: A comb-line filter incorporating a plurality of bandpass resonators set off center between ground planes is provided with input and output coupling means comprised of dual notching resonators.

Abstract: A distributed TEM resonator band pass filter has a set of rod-shaped resonators arranged in an interdigital line with alternate ones of the resonators being grounded to opposite walls of a housing. Each resonator has an ungrounded end which is capacitively coupled to a wall of the housing. Partitions, grounded to the housing, are located between successive ones of the resonators. Each partition closes off only a portion of the space between neighboring resonators to leave a coupling aperture. The interdigital arrangement provides for reduced loss and a higher Q. Input and output ports are provided at opposite ends of the interdigital line. The resonators may be constructed in the form of a suspended substrate, a stripline, or a microstrip configuration.

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: In a dielectric filter comprising a dielectric block having outer conductors formed on the outer surfaces of the dielectric block, first and second arrays of through holes are formed in the dielectric block and have inner conductors formed on the inner surfaces thereof. A plurality of stages of dielectric resonators are constructed by the inner conductors formed in the through holes of the first array, the dielectric substance of the dielectric block and the outer conductors formed on the dielectric block, and the neighboring resonators of the first array are coupled to one another to form a band pass filter portion. Further, another plurality of stages of resonators are constructed by the inner conductors formed in the through holes of the second array, the dielectric substance of the dielectric block and the outer conductors formed on the dielectric block, and each of the resonators of the second array and those of the band pass filter portion are coupled to each other at each stage.

Abstract: A polarity reversal network is provided for a microwave filter that includes a plurality of resonators. The polarity reversal network has a magnetic coupling device that is positioned within an iris of the filter between a pair of the resonators. The coupling device is tunable to adjust its resonant frequency and is used to magnetically couple a signal from a first one of the pair of resonators to a second one of the pair of resonators. The coupling device also reverses the polarity of the magnetically-coupled signal upon the resonant frequency being tuned below a passband frequency of the microwave filter. As a result, the polarity of the signal resembles that of a capacitively-coupled signal.

Abstract: A multioctave multiplexer (10) with multiple independent filter channels with a circuit topology that employs a planar circuit segment (18) and conventional combline resonator circuits (38), (40) and (42). The planar circuit segment (18) forms a common input (28) etched on a substrate and concurrently feeds RF signals to the independent channels (12), (14) and (16). The first planar circuit segment (18) comprises two unit elements (51) and (52) and a .pi.-section capacitor network (54), (56) and (58). The second combline circuit segment (38) comprises shunt resonators (38a), (38b), and (38c) and inter-resonator inductors (44a), (44b) and (44c) . The first and second circuit segments generate a number of transmission zeros on a complex plane that is 2 at DC, 2N-4 at one-quarter wavelength and 2 at the complex frequency of S=+/-1 in the complex plane.

Abstract: A filter housing has a series of linearly spaced resonators positioned in the housing. The resonators each include a conductive rod upstanding from a bottom wall of the housing. At least one coaxial cable portion has a first connecting section extending along a housing upper wall or housing cover, the cable portion having integral end sections including an inner conductor of the coaxial cable portion, extending variously into proximity to the conductive rods of a selected first two of the series of resonators, the first two of the resonators having at least one other resonator of the series of resonators extending therebetween. The periphery of the resonators may be configured variously with half or full circular or half or full elliptical peripheries. The filter may be diplexer or in higher degrees of multiplexing.

Abstract: A coaxial resonator of modular construction, wherein the resonator is formed from two or more blocks, or modules, that are fastened to each other. Conductively plated surfaces of the modules may form the center conductor and at least part of the shield of the resonator. A dielectric layer is formed at least partially from the module material, typically ceramic. The module blocks are advantageously made by being cut from ceramic substrate. A resonator, or filter including at least one resonator, can be manufactured without special tools, and may be fabricated by manually assembling modules or by using automatic assembly methods, such as by known printed circuit board assembly techniques.

Abstract: A wave filter having two or more dielectric resonators of substantially tubular shape juxtaposed on a base structure with their longitudinal orientations reversed alternately. The resonator terminals are therefore staggered on both sides of the juxtaposition of the resonators and thus better electrically isolated from one another than if all the resonators are oriented in the same longitudinal direction. The base structure is of ceramic material, having coupling elements, terminals, and all necessary electrical connections formed thereon or embedded therein.

Abstract: A single-stage dielectric band elimination filter has a dielectric block with its outer surfaces mostly covered by an outer conductor and two mutually coupled resonant lines formed therein. Each resonant line has an open end insulated from the outer conductor and a shorted end connected thereto, the open and shorted ends of the two resonant lines being oppositely oriented. A multi-stage dielectric filter has a plurality of such single-stage band elimination filters formed inside a dielectric block, each mutually adjacent pair of the single-stage band elimination filters being interdigitally coupled or combline-coupled to each other with phase shift of II/2 therebetween. The open end of a resonant line may be formed at one of the end surfaces of the dielectric block, being connected to an electrode insulated from the outer conductor, or at an annular conductor-free area formed on the inner surface of the corresponding throughhole.

Abstract: Cavity filter with comb-line structure having a steep-flanked flanked pass-band. To obtain this steep flank, rejectors are positioned in the vicinity of the access bars of the filter, orthogonally to the teeth of the comb-line structure. The best results are obtained for the flanks corresponding to the high frequencies of the pass-band, namely with rejectors tuned to frequencies higher than the center frequency of the pass-band.

Abstract: A ceramic filter (100) with a transmission zero is disclosed. The filter (100) includes a block of dielectric material having top (102), bottom (104), and side surfaces (106, 108, 110 and 112), and having two or more metallized through-holes extending from the top to the bottom surfaces (102, 104), defining approximately half wave long resonators. The surfaces are substantially covered with a conductive material defining a metallized layer, with the exception that the top surface (102) is substantially uncoated, and with the additional exception that the bottom surface (104) is also substantially uncoated defining a filter with an open circuit at both ends. The filter (100) also has an input and an output (118, 120) and a mechanism or slot for electrically isolating successive resonators, extending about halfway between the top (102) and bottom surface (104). A filter constructed as detailed above, can have a higher Q value and lower insertion loss.

Abstract: A wave filter having two or more dielectric resonators of substantially tubular shape juxtaposed on a base structure with their longitudinal orientations reversed alternately. The resonator terminals are therefore staggered on both sides of the juxtaposition of the resonators and thus better electrically isolated from one another than if all the resonators are oriented in the same longitudinal direction. The base structure is of ceramic material, having coupling elements, terminals, and all necessary electrical connections formed thereon or embedded therein.

Abstract: A dual-band filter providing a bandpass characteristic over a first predetermined range of frequencies, and a notch, or band-reject characteristic over a second predetermined range of frequencies. In one embodiment, the notch characteristic occurs within the bandpass characteristic, yielding a filter frequency response with two asymmetric passbands separated by a reject band. This is particularly suited to cellular Band A receive filter applications, but the design is easily adapted to other uses. Appropriate tuning can restore symmetry to the passbands.

Abstract: The present invention relates to a filter employed in a radio communication apparatus and has as an object to prevent characteristics of the filter from degradation by increasing unloaded Q of strip line resonators of the filter.

Abstract: An RF filter having a housing defining a cavity with plural elongated resonators and plural resonator decouplers adjacent each of plural pairs of the resonators in the housing. The decouplers are grounded adjacent each of their ends only to the housing to provide an enhanced resonator decoupling effect. The filter may instead comprise a dielectric block with resonator holes and resonator decoupler holes each appropriately metalized with the decoupler holes being grounded at each end at external metalized block surfaces.

Abstract: The sweep rate limitations that heretofore have constrained the maximum sweep rates of swept analysis instruments are obviated by optimizing filter circuitry and post-processing the IF signal using various techniques to compensate for errors caused by fast sweeping. Some selective windowing is also used to compensate for distortions due to fast sweep rates.

Abstract: The invention relates to a comb-line high-frequency filter or the like, comprising an elongated casing (1) of an electrically conductive material, conductor rods of an electrically conductive material being arranged in a sequence at predetermined intervals in a substantially integral air cavity within the casing, one end of each conductor rod being short-circuited to the casing and its other end being detached therefrom so that each conductor rod forms with the casing (1) an air-insulated coaxial resonator. In each coaxial resonator, the ratio between the diameters (X, Y) of the casing (1) and the resonator (3) is within the range from about 2.8 to 3.3.

Abstract: A poly-band filter includes a folded metal housing which defines an interior region partitioned by a divider. First and second pluralities of resonators are provided in the housing. Alternately increasing and decreasing degrees of coupling are provided between adjacent resonators in the housing. Slot coupling is provided between first and second non-adjacent resonators displaced from input/output connectors for the filter.

Abstract: There is disclosed a tunable notch filter which has a bandpass characteristic and where a tunable notch is added to the bandpass filter by placing a resonator outside the input or output probe of the bandpass filter. The bandpass filter is a resonant type of filter and comprises a plurality of parallel, spaced apart resonators. The tunable notch resonator is positioned near the input or output probe and operates to direct a substantial amount of energy from the filter at the frequency at which the notch resonator is tuned. In this manner a notch is created within the bandpass characteristic of the filter and which notch resonator can be tuned to provide the notch anywhere in the filter passband or above or below the band edges.

Abstract: A high-frequency bandpass filter, including several cylindrical conductor rods (3, 4) arranged in a line with predetermined spacings in a continuous space defined by an elongated housing (1) made of an electrically conductive material and closed on all sides, each conductor rod being attached and short-circuited at its first end to the housing (1) and spaced apart from the housing at its second end so that each conductor rod forms a coaxial resonator together with the housing. The second end of each conductor rod includes a portion (4) larger in diameter as compared with the remaining portion of the conductor rod, and the type of a coupling between two adjacent coaxial resonators is arranged to be set to be predominantly capacitive or predominantly inductive by adjusting the ratio of the distance between the first ends of the conductor rods (3, 4) of the coaxial resonators to a distance between the portions (4) with a larger diameter.

Abstract: A strip line filter which has a plurality of resonance electrodes on one major surface of a dielectric substrate. A guard electrode is formed on a side of the dielectric substrate and connects the resonance electrodes with a grounding electrode which is formed on the other major surface of the dielectric substrate. Each of the resonance electrodes has a narrow portion in a side near the guard electrode and a wide portion in an open end side. Capacitances generated between the resonance electrodes and the grounding electrode and the inductances of the resonance electrodes form LC resonance circuits. In other words, the resonance electrodes, the dielectric substrate and the grounding electrode form resonators.

Abstract: An interdigital bandpass filter is provided which presents improved performance and is easy to manufacture. The filter is provided with a resonator plate which includes a plurality of resonator elements formed integrally with the resonator plate. For defining a space for accommodating these resonator elements, spacer plates are formed with respective openings. The filter is assembled by stacking the spacer and resonator plates and case plates and securing them to each other. Input/output conductors are coupled to the resonator elements through coaxial line coupling portions which are provided in such a manner that they extend in directions intersecting with the plane of the resonator plate toward the accommodating space.

Abstract: Interdigitation and surface mounting of a block filter that has at least a first resonator and that has at least a first pole and at least a first zero in its transfer function provides a surface mountable block filter having selectable frequency rejection response operation.

Abstract: This microstrip comb line filter includes a planar dielectric substrate, and a planar ground member positioned on one side of the dielectric substrate and extending along a first portion of the substrate. There is a second portion of the substrate along which the ground member does not extend, thereby forming a cavity filled with air. A plurality of generally parallel, electromagnetically coupled and spaced-apart, elongate microstrip conductors are positioned on the other side of the dielectric substrate. One end of each of the conductors is positioned adjacent to the first portion of the substrate and connected to the ground member. The other end of each of the conductors is electrically spaced from the ground member and positioned adjacent to the second portion of the substrate. The air cavity extends along at least half the length of the conductors.

Abstract: Band pass filter incorporated in a duplex base station cellular telephony transmit/receive system have aluminum parts having plated thereon a composite coating which is entirely of nonferromagnetic materials (to reduce creation in the filter of intermodulation products) and which consists of a zinc layer on an aluminum substrate and copper and silver layers outward in that order from the zinc layer and having respective thickness of at least about 300 microinches, and of at least about 500 microinches (to reduce resistance losses incurred by microwaves traveling throughout the filter). The filters also include other parts which are interiorly of brass and some of which are silver plated, all to the end of further reducing such intermodulation products and losses. The filters have input and output ports provided by coaxial fittings press fitted into bores in a wall of the filter to thereby reduce intermodulation products caused by contact non-linearities.

Abstract: A technique for directly coupling multiple high frequency resonant cavity filters includes a common port 62 that is directly coupled to a coupling rod 76 that is mounted within a first high frequency resonant cavity filter housing 64 of a housing assembly 60. The coupling rod 76 is directly coupled by a conductor 74 to an coupling rod 72 that is mounted within a second high frequency resonant cavity filter housing 66. The conductor 74 passes through an opening 78 in a common wall 80 between the first 64 and the second 66 high frequency resonant cavity filter housings. Thus, both filters 64, 66 are directly coupled to the common port 62.

Abstract: An inexpensive and lightweight air insulated high frequency filter can be made utilizing a radio device's frame and a printed board (15) intended for electrical circuits, so that during manufacture of the printed board (15) it is machined so that several side by side finger-like projecting tongues (14.sub.1, 14.sub.2, 14.sub.3, 14.sub.4) are formed, which are entirely coated with electrically conducting material. Thereafter the printed board, on which electrical and mechanical components intended for it are mounted, is placed in the radio device's crate-like frame made of conducting material and possibly provided with partition walls (18, 19), and on which also cover parts are fastened so that the tongues will be parallel with them and located between them, whereby the tongues, the enclosing cover parts and the frame wall parts form a filter structure.

Abstract: A coaxial fitting comprises, a metallic tubular ferrule having a forward portion with knurling thereon and a rearward portion with external threads thereon by which such fitting is coupleable to a coaxial cable, the fitting also comprising an inner metallic rod conductor extending in the ferrule in concentric radially spaced relation therewith, and a dielectric plug disposed in the ferrule radially in contact with the ferrule and inner conductor to maintain them in fixed relation, the plug being longitudinally in contact with an inwardly projecting internal annular shoulder in the ferrule. The knurled portion of the fitting is adapted to be press fitted into a bore formed in the housing of a microwave device to provide a port for microwaves supplied to or from such device. The metallic parts of the fitting interiorly comprise copper and have precious metal platings thereon to reduce microwave resistance losses.

Abstract: A folded high frequency resonant cavity filter 30 includes a filter housing 32 that contains a half-wave resonator rod 36, 64 and a plurality of evanescent mode resonator rods 34, 34'. The half-wave resonator rod 36, 64 and plurality of evanescent mode resonator rods 34, 34' are mounted to the filter housing 32 such that they all lie along a single plane. The filter housing 32 has an inner wall 42 that physically isolates two groups of evanescent mode resonator rods 34, 34' from each other. An aperture 40 is is formed in the inner housing wall 42 between two physically opposing evanescent mode resonator rods 34' to allow a capacitive cross-coupling to occur between the two evanescent mode resonator rods 34'. The capacitive cross-coupling is fine tuned by a tuning rod 44 that is positioned through the inner wall 42 and within the aperture 40.