Abstract: Microwave hairpin-comb filters utilize a plurality of hairpin (i.e., folded) half-wavelength microstrip or stripline resonators arranged side-by-side and all with the same orientation. The coupling regions between resonators extend parallel to the sides of the resonators for substantially 1/8 to 1/4 wavelength at the frequency of resonance of the resonators. This length of coupling region between resonators, along with all resonators being oriented in the same direction, result in resonance effects in the coupling regions between the resonators. These effects greatly reduce the couplings between the resonators so that the resonators can be very closely spaced so as to produce a compact filter structure yet still have a narrow passband. For example, a compact narrow band filter structure is possible using high-Q nominally half wavelength hairpin resonators. The structure can also be made to produce poles of attenuation adjacent to the passband in order to enhance the filter cutoff characteristic.

Abstract: A resonator mounting mechanism includes a stand having a groove in the head of the stand. A cap, which also has a groove, fits over the top of the stand to hold a resonator in place. The stand has two slots formed between lugs, which receive arms on the cap. The sidewalls of the lugs forming the slots and the arms on the cap are tapered so that there is an interference fit between the cap and the stand. The interference fit between the slots and arms holds the cap, stand, and resonator in a fixed position. The bottom of the stand includes structure for attaching the stand to a wall of a resonator cavity, or the like.

Abstract: A resonant via-type connection between layers of a multilayer support structure having, at predetermined RF frequencies, a very low, effectively short circuit impedance. The resonant vias utilize the inductance of a via post by forming it into a resonant circuit with a capacitance at the via's distal end coupled to another conductor. A plurality of resonant vias can be formed having respective plurality of resonant frequencies to form a wideband connection. The capacitances at the vias' distal ends coupling to another conductor can be formed to resonate with the total series inductance of the via post and of wire connections to an attached device.

Abstract: An electromagnetic shield for an NMR radio frequency coil designed to resonate at a selected Larmor frequency. The shield includes an electrically conductive layer surrounding the coil. This electrically conductive layer has a thickness substantially the same as one skin depth at the selected Larmor frequency. As such, the conductive layer efficiently conducts radio frequency currents at the selected Larmor frequency thereby conducting and containing the radio frequency coils at the selected Larmor frequency within the coil. Simultaneously, an electrically conductive layer, due to its thinness, very inefficiently conducts eddy currents of the type induced by the lower frequency DC gradient current switching transients the gradients are utilized to magnetically localize an image slice or volume.

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A stripline filter is disclosed having two stripline resonators which are mutually coupled. In order to be able to influence the type of coupling, such as inductive, capacitive or a combination thereof, the distance between the stripline resonators changes along their length. If the stripline resonators are shorted at the end where the distance between them has a minimum value, then the coupling is substantially inductive. If the stripline resonators are open or capacitively loaded at the end where the distance between the resonators has a minimum value, then the coupling is substantially capacitive.

Abstract: An antenna having a high gain, of small-size, and capable of setting the radiation direction of electromagnetic waves in a desired direction. The antenna also allows electromagnetic waves to be radiated stably. The antenna has a first planar conductor shaped like a flat plate. Disposed on the first planar conductor is a bar-shaped dielectric strip having one end connected to a waveguide or a transmission circuit and the other end being an open end which does not reach the position of openings in a second covering planar conductor. The end surface of the open end of the dielectric strip is shaped like a flat surface, and a column-shaped dielectric resonator is disposed at the open end side on the extension axis of the dielectric strip. A surrounding member is provided around the side of the dielectric resonator so as to surround it with a space therebetween.

Abstract: A filter has a shell construction including a connection surface and a bar-like resonator in the shell construction. The bar-like resonator has an initial section having one end region thereof connected to the connection surface of the shell construction and an opposite end region. A substantially straight and elogate intermediate section extends from the opposite end region of the initial section to an end and a turning-point section extends from the end of the intermediate section to an end. A substantially straight and elongate end section has one end connected to the end of the turning-point section so as to extend adjacent to the intermediate section and supporting means connect to the connection surface of the shell construction for supporting the bar-like reasonator at least at one of the end section and turning-point.

Abstract: A resonator includes a substrate to which are attached trimmable capacitance and inductance portions which together with a varactor and transistor form an oscillator circuit. The substrate mounts orthogonally in a slot on an oscillator board to reduce microphonic effects from a cover that otherwise would degrade the oscillator performance.

Abstract: A resonant structure and filter include a resonant element mounted to the cover of a housing. A transmission line passes through the cover and is connected to a coupling loop. The coupling loop is located adjacent the resonator and is connected to ground. A coupling tuner is attached to the housing and includes a post which is movably attached to the housing. The tuner extends between the coupling loop and the resonator, and may be adjusted to change the electromagnetic coupling.

Abstract: An electromagnetic filter has a unitary filter body defining a number of cavities. A cover for the filter body has several resonators attached to it which are located in the cavities when the cover is attached to the filter body. The cover has a recess into which a transmission line is placed. Passageways through the cover connect the transmission line with coupling mechanisms mounted on the cover adjacent the resonators. The resonators have a generally toroidal shape and the coupling mechanisms are shaped to provide the desired coupling between the transmission line and the resonators. An adjustable capacitor attached to the coupling loop has a passageway through its housing to eliminate moisture from the capacitor. The resonator and cavities may be tuned by use of a tuning mechanism which is also designed to minimize moisture which might prevent movement of the tuner during tuning.

Abstract: An electromagnetic filter includes a plurality of dielectrically-loaded split-ring resonators. The resonators are oriented side-by-side generally within a single plane to achieve side-coupling. The side-coupled orientation of the resonators allows adjacent resonators to be set apart at a distance to achieve electrical coupling. Both the side-coupled orientation of the resonators and the dielectric-loading result in significant volumetric reductions without detrimental decreases in the quality factor of the filter. Coupling screws disposed between adjacent resonators provide further control over the coupling between adjacent resonators.

Abstract: A low-radiation balanced microstrip bandpass filter is provided. A series of microstrip segments are arranged on the surface of a substrate. The degree of coupling between adjacent pairs of segments is determined by the length of overlap between them. By always having pairs of segments, a very small far field radiation is achieved.

Abstract: A high Q planar resonator (200) which includes a plurality of interconnected planar runners (209, 211, 213) which decrease in width on multiple layers of substrate material (203). The invention produces a high Q by using multiple conductor layers as the center conductor to reduce current crowding.

Abstract: A volume efficient resonator (100) includes a helical coil transmission line (108) fabricated on a plurality of dielectrics (212, 214, 216, 218, 220, 222, 224, and 226). The transmission line (108) includes selectively metalized areas (210) on the dielectric layers. The metalized areas are formed in half loops and interconnected at alternate terminals via through-holes (203 and 205). A distributed capacitor (106) is added to the transmission line (108) using another set of selectively metalized areas (208). The distributed capacitor (106) is shunted to a ground plane (202) via through-holes (204, 206).

Abstract: A stripline filter includes a ceramic substrate having first and second mutually opposite side surfaces and an end surface. At least one stripline resonator is disposed on the first side surface. Capacitive coupling structures are disposed at the end surface for coupling a high-frequency signal in and out. Ground metallizing covers the ceramic substrate except for the first side surface and the end surface. The coupling structures are formed by coupling metal surfaces being disposed on the second side surface and a galvanic separation being disposed on the second side surface and separating the coupling metal surfaces from the ground metallizing; metal surfaces being disposed on the first side surface and being galvanically separated from the stripline resonators; and through holes being formed in the ceramic substrate for galvanically connecting the coupling metal surfaces and the metal surfaces to one another through the through holes.

Abstract: A microwave bandpass filter has a planar configuration formed in microstrip or stripline where a circuit is printed onto a substrate. The filter has at least two patch resonators with a T-shaped coupling path extending between the two resonators. In a further embodiment of the invention, one or more resonators is isolated from other resonators in the filter by being located in a compartmentalized housing or separate housings to eliminate undesirable coupling between a resonator in one compartment and a resonator in another compartment. The filter of the present invention has improved performance characteristics over previous patch resonator filters.

Abstract: A coplanar band pass filter having a centerline formed of at least first and second serially arranged conducting segments which are separated by a gap. The centered segments are flanked by a resonator for coupling return current from the first and second segments. Conducting members that may include conductive strips or conductive planes are respectively provided on opposing sides of the resonator and centerline. Band pass elements may be provided in the conductive strips or planes to reduce or eliminate spurious pass band frequencies.

Abstract: A thin-film multilayered electrode of a high frequency electromagnetic field coupled type is disclosed. The thin-film multilayered electrode comprises thin-film conductors and dielectric thin films alternately stacked on a dielectric substrate so that a plurality of TEM mode transmission lines are multilayered. A film thickness of each of the dielectric thin films is set so that phase velocities of TEM waves which propagate through at least two of the plurality of TEM mode transmission lines are made substantially equal to each other, and a film thickness of each of the thin-film conductors is set so as to be smaller than a skin depth of a frequency which is used so that electromagnetic fields of at least two of the plurality of TEM mode transmission lines are coupled with each other.

Abstract: The invention relates to a stripline resonator structure comprising a substrate (2) and one or more stripline patterns (3 to 7) formed on the substrate as a conductive coating. The stripline patterns (3 to 7) are formed as the conductive coating of projections protruding from the actual substrate material and being made of the substrate material.

Abstract: A bandpass filter having 4-degrees of freedom includes a plurality of resonant cavities having respective Qs where at least one of the Qs is different. A plurality of main couplings couple successive resonant cavities to establish a main signal path that provides a first degree of freedom for controlling the shape of the filter's frequency response over its passband. A plurality of bridge couplings couple pairs of the resonant cavities so that the cavities are connected in a canonical circuit topology. The bridge couplings provide second and third degrees of freedom for controlling the sharpness of the frequency response 's transition between its passband and stopband and controlling the linearity of its phase, respectively. The cavities' non-uniform Qs provide a fourth degree of freedom for controlling the amplitude of the filter's frequency response in the passband so that the amplitude is within a predetermined tolerance of a desired passband shape.

Abstract: A resonator includes a substrate (15) having a first dielectric constant, an insulative layer (16, 31) overlying the substrate (15) and having a second dielectric constant wherein the second dielectric constant is lower than the first dielectric constant, and a electrically conductive layer (11) overlying the insulative layer (16, 31). The resonator has a higher "Q" factor than the prior art.

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A strip line filter has a switching function for being operated without connecting a separate switch to a front end and a back end of the filter for preventing transmission electric power from being lost by a receiving unit, to thereby make the size of the transmitting and receiving system smaller. The strip line filter has a switching function in a transmission line filter, comprising: an inputting unit resonator and an outputting unit resonator, with the inputting unit resonator having a first open stub and a second open stub with the first open stub connected to ground through at least one capacitor; and the outputting unit resonator has a third open stub and a fourth open stub with the third open stub connected to ground through at least one capacitor, and being positioned within a distance of about one wavelength of a pass band frequency from the inputting unit resonator.

Abstract: The invention relates to a resonator coupling and a radio frequency filter, which comprise a transmission line resonator (106), preferably a helix resonator, having an upper and lower end, a transmission line (108, SL3) for coupling to the resonator, and a tap point (121), at which the transmission line (108, SL3) and the transmission line resonator (106) are in direct contact with each other, whereby the transmission line (106) is divided at the tap point (121) into a lower and upper part, the lower part comprising a first part (SL1) and the upper part comprising a second part (SL2). A coupling element (SL4) is placed at the tap point (121) in parallel with the transmission line resonator (106), coupled (M1) electromagnetically to the transmission line resonator (106), thus improving the stop/pass ratio of the filter.

Abstract: The invention relates to a resonator structure and radio frequency filter in which the resonating frequency of a transmission line resonator can be switched in a stepwise manner between at least three values. The switching is implemented as follows: a regulating element including a switch that has at least three states is arranged in connection with the resonator. The three states of the switch correspond to different values of the specific impedance and, hence, the resonating frequency of the transmission line resonator. The regulating element is in accordance with a known arrangement: it may be e.g. a coupling element formed of a strip line on the surface of a low-loss substrate or ceramic, or a side circuit including a capacitive and inductive element, coupled to the resonator.

Abstract: An inductive element having a selectable inductive value is connectable to a differential circuit. The inductive element is formed of transmission lines, and the inductive value of the inductive element is altered by trimming away portions of the transmission line while maintaining the inductive element in balance with the differential circuit.

Abstract: The invention relates to a radiofrequency filter in which the coupling between the transmission line resonators is effected by using both a slot coupling and a link coupling. The coupling slot and the coupling link are designed so that changes of the coupling intensity in the link coupling caused by shifting of the resonator element is of the same size and of the opposite sign as a corresponding change in the slot coupling, whereby the changes compensate one another. The design is based on the fact that the distance of the coupling link from the resonator is longer close to the coupling slot than far away from the coupling slot.

Abstract: The planar superconducting resonator includes a substrate (1), a symmetrically shaped stripline (2) applied to the substrate (1) in which two orthogonal electromagnetic modes are excitable and including a symmetry perturbation for coupling the two orthogonal electromagnetic modes, an additional stripline (5) arranged on the substrate in the vicinity of the symmetry perturbation, a Josephson junction (3) arranged between the symmetry perturbation and the additional stripline (5) and a device for generating and controlling a magnetic field at the Josephson junction (3) so that the degree of coupling between the two orthogonal electromagnetic modes is varied. The Josephson junction (3) is formed by a non-superconducting layer (4) arranged between the symmetry perturbation and the additional stripline (5).

Abstract: A dielectric antenna duplexer used in a high frequency radio device such as a portable telephone, and a dielectric filter for forming the duplexer of the SIR (stepped impedance resonator) composed by cascade connection of first transmission lines having one end grounded and second transmission lines having one end open and lower in characteristic impedance than in the first transmission lines, first transmission lines and second transmission lines are individually coupled in electromagnetic field, thereby forming an antenna duplexer and a dielectric filter of small insertion loss, high bandwidth selectivity, excellent band pass characteristic, and low cost.

Abstract: High power high temperature superconductor filters having TM.sub.0i0 mode (i=1, 2, 3, . . . ) circular shaped high temperature superconductor planar resonators or symmetrical polygon shaped resonators which eliminates wrap-around H-field and very sharp current peaks at the edge of the resonator are provided.

Abstract: A novel LC-type network consisting of distributed inductors and capacitors realized by means of printed patterns on a printed circuit board is disclosed. The LC-type network is based on a dielectric strip line two terminal resonance circuit consisting of a capacitance and inductance in parallel which forms a high Q resonator suitable for application in the construction of high frequency filters and oscillators. Constructing the resonator on a printed circuit board provides for high accuracy and repeatability. In addition, the need for trimming and/or tuning is eliminated thus lowering production costs.

Abstract: A strip dual mode loop resonator includes a loop-shaped strip line having a pair of straight strip lines arranged in parallel, an electric length of the loop-shaped strip line being equivalent to a wavelength of a microwave circulated in the loop-shaped strip line in two different directions according to a characteristic impedance of the loop-shaped strip line, and the straight strip lines being coupled to each other in electromagnetic coupling to change the characteristic impedance of the loop-shaped strip line. The microwave is transferred from an input strip line to the loop-shaped strip line through electromagnetic field induced by the microwave. Thereafter, the microwave is reflected in the straight strip lines of the loop-shaped strip line to produce reflected microwaves circulated in opposite directions. Thereafter, the reflected waves are resonated and filtered in dual mode in the loop-shaped strip line.

Abstract: The invention relates to a radio frequency filter comprising at least two helix resonators (HX1-HX2) placed at a distance from each other, each of which is wound of a metal wire into a cylindrical coil. A conductor (MLIN2), preferably a microstrip line, runs between two neighboring resonators and is provided at a distance (d1, d2) from each of the resonator coils so that one part (3) of it is electromagnetically connected to one resonator (HX 1) and the other part (4) is electromagnetically connected to another resonator (HX2).

Abstract: A strip-line filter is provided with upper- and lower-stage resonators having the same electromagnetic characteristics. Each of the resonators has a one-wavelength square-shaped strip line and four open-end transmission lines connected to four coupling points A,C,B and D (or E,G,F and H) of each resonator which are spaced 90 degrees in electric length in that order. The square-shaped strip lines have a pair of parallel coupling lines closely placed in parallel to each other to electromagnetically couple the resonators. Therefore, the filter can be manufactured in a small size. A first microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points A and B (or E and F), and a second microwave resonated in each resonator is electromagnetically influenced by two open-end transmission lines connected to two coupling points C and D (or G and H).

Abstract: A strip dual mode filter includes a strip line ring resonator having a uniform line impedance and an electric length equivalent to a wavelength of a microwave, an input terminal coupled to a point A of the ring resonator, a feed-back circuit connected to points C and D and arranged in a central hollow space of the ring resonator and an output terminal coupled to a point B of the ring resonator. The points A to D are spaced by a quarter-wave length of the microwave in that order. The microwave input to the point A is resonated in the ring resonator in a first mode and is input to the feed-back circuit from the point C. Therefore, a phase of the microwave shifts by a multiple of a half-wave length of the microwave, and the microwave is output to the point D. Thereafter, the microwave is resonated in the ring resonator in a second mode orthogonal to the first mode and is output from the point B to the output terminal.

Abstract: In a laminated dielectric resonator, twomo strip line is formed and resonant frequency is lowered. Accordingly, the length of the resonator is reduced, and the length of the strip line becomes shorter than one fourth of the wavelength with the lowered resonant frequency, which leads to further reduction of the length of the resonator. By lowering the resonant frequency, dielectric material with less relative permittivity can be used, with a result of resonator with high unloaded Q and excellent temperature characteristic. Further, at least one coupling electrode is formed as external or internal electrode to compose a capacitor together with a second strip line, and a laminated dielectric resonator is connected to an external circuit via the coupling electrode. A dielectric filter such as band pass filter, band elimination filter is so composed that the dielectric resonators are cascade-connected to one another.

Abstract: A planar filter is proposed in which a plurality of striplines arranged next to one another on a substrate are supplemented by an overcoupling stripline which couples to one another two striplines which are not immediately neighboring. The length of the overcoupling stripline is an integral multiple of a half wavelength of the center frequency of the filter.

Abstract: In a laminated dielectric resonator, two-fold strip line is formed and resonant frequency is lowered. Accordingly, the length of the resonator is reduced, and the length of the strip line becomes shorter than one fourth of the wavelength with the lowered resonant frequency, which leads to further reduction of the length of the resonator. By lowering the resonant frequency, dielectric material with less relative permittivity can be used, with a result of resonator with high unloaded Q and excellent temperature characteristic. Further, at least one coupling electrode is formed as external or internal electrode to compose a capacitor together with a second strip line, and a laminated dielectric resonator is connected to an external circuit via the coupling electrode. A dielectric filter such as band pass filter, band elimination filter is so composed that the dielectric resonators are cascade-connected to one another.

Abstract: Electromagnetic resonators according to the invention comprise a first body, exemplarily a split thin ring, that is disposed between two planar field confining plates. The thickness (t) of the first body is less (typically less than 1/2 or 1/10) of the outer radius (R) of the body, and the distance between the first body and the confining plates is less than R. In preferred embodiments the first body comprises superconducting material. Resonators according to the invention can be readily assembled into relatively compact filters that are easily tunable, can have large quality factor, and offer the possibility of single mode operation. Such filters can advantageously be used in, e.g., wireless communications systems.

Abstract: A resonator having a small size and/or a high Q value, for use in forming a filter with low insertion loss in spite of its small size. According to one aspect of the invention, a resonator includes a laminated body 22. The laminated body 22 includes a first dielectric layer 24a. On one surface of the first dielectric layer 24a, a loop shaped line electrode 26 and a strip shaped take-out electrode 28 are formed. On the other surface of the first dielectric layer 24a, a first earth electrode 30a and a first protection layer 34a are formed. On one surface of the first dielectric layer 24a, a second dielectric layer 24b is formed so as to cover the line electrode 26. On the second dielectric layer 24b, a second earth electrode 30b and a second protection layer 34b are formed. On side faces of the laminated body 22, six external electrodes are formed. One external electrode used as an earth terminal is connected to one end of the line electrode 26 and a lead-out electrode 32a of the first earth electrode 30a.

Abstract: A strip dual mode loop resonator includes a loop-shaped strip line having a pair of straight strip lines arranged in parallel, an electric length of the loop-shaped strip line being equivalent to a wavelength of a microwave circulated in the loop-shaped strip line in two different directions according to a characteristic impedance of the loop-shaped strip line, and the straight strip lines being coupled to each other in electromagnetic coupling to change the characteristic impedance of the loop-shaped strip line. The microwave is transferred from an input strip line to the loop-shaped strip line through electromagnetic field induced by the microwave. Thereafter, the microwave is reflected in the straight strip lines of the loop-shaped strip line to produce reflected microwaves circulated in opposite directions. Thereafter, the reflected waves are resonated and filtered in dual mode in the loop-shaped strip line.

Abstract: A high Q multi-layer ceramic transmission line resonator (100) used for RF applications. The resonator (100) includes a plurality of strips (102) which are separated by a ceramic substrate (104). Each of the strips are interconnected using vias (110) passing through the ceramic substrate (104). The invention utilizes current manufacturing processes to fabricate an equivalent thick center conductor to effectively increase the Q factor. This allows for the resonator to be used in miniature RF communication devices utilized in high tier devices such as voltage controlled oscillators (VCOs) or integrated filter circuits.

Abstract: A filter for processing electromagnetic signals has a housing with resonators located inside the cavity of that housing. The resonators, which may be made in part from superconducting material, have rounded exterior surfaces without corners to provide a more desirable coating surface and uniform electric field around the resonators. The filter housing may be composed of a plurality of housing cells, each containing a resonator. These cells can be removably attached to other cells so that resonators may be added to or removed from the filter as may be required for a particular application.

Abstract: A strip dual mode filter consists of a strip line ring resonator having an electric length equivalent to a resonance wavelength .lambda..sub.o for resonating microwaves at the resonance wavelength .lambda..sub.o according to a characteristic impedance thereof, an input coupling capacitor for transmitting the microwaves from an input terminal to a coupling point A of the ring resonator, an output coupling capacitor for outputting the microwaves resonated in the ring resonator from a coupling point B of the ring resonator to an output terminal, and a phase-shifting circuit connected to a coupling point C and a coupling point D of the ring resonator for changing the characteristic impedance of the ring resonator by shifting a phase of the microwave by a multiple of a half-wave length of the microwaves.

Abstract: A layered stripline filter has input and output electrodes formed on a dielectric layer, two resonant elements disposed on the dielectric layer and having ends connected to a ground electrode, providing a quarter-wave stripline resonator, an inductive coupling adjustment electrode disposed on the dielectric layer intermediate between the two resonant elements and having opposite ends connected to the ground electrode, and a coupling electrode disposed on the dielectric layer in overlapping relationship to portions of the two resonant elements. The layered stripline filter is small in size and has a desired bandwidth achieved by adjusting the inductive coupling between the two resonant elements. The layered stripline filter has an attenuation peak spaced from the passband thereof, resulting improved attenuation and spurious characteristics.

Abstract: The present invention relates to a coupling element (21) by which the coupling of a resonator (24) is adjusted in a radio frequency filter. The coupling element of the invention is a strip made of flexible conductor material being shaped symmetrical relative to the normal, that is, the symmetry axis of the longitudinal axis extending via the centrepoint of the strip in the longitudinal direction. The strip (21) is fixed at least at two points of an edge in the longitudinal direction to the circuit board (25) either by surface mounting on pads (33, 35, 36) or by soldering into holes borred in the circuit board to be at appropriate space from the resonator coil (34) and from the surface of the circuit board (25). One (33) of the fixing points is grounded and another (36) is connected to the signal conductor in the filter. The coupling can easily be adjusted by bending the board relative to the symmetry axis either one-sidedly or on both sides.

Abstract: A resonator mounting mechanism has a stand which can be attached to a wall. The stand has two wings and a groove in between the wings. A cap also has wings and a groove in between the wings where the cap is placed over the stand so that the grooves form an opening for receiving a resonator. The wings on the stand are secured to the wings on the cap by rings. The grooves in the stand and cap may have a uniform circular cross-section or may be curved to accommodate various curved resonator shapes.

Abstract: The present invention relates to a radio frequency filter the resonators (6,7) of which are made up of a wire wound into a cylindrical coil comprising a number of turns and of a surrounding casing (41). Finger-like projections (3) of an insulating plate (1) support the conical coils from the inside, and the coupling to the resonator is from a microstrip line (8), at a tap point (21), on the insulating plate. Each cylindrical coil has, adjoining the first turn, a straight portion (2) which is parallel to the axis of the cylindrical coil and extends towards the bottom plate (44) of the filter. On the inside surface of the bottom plate (44) there is a lead (51) one end (E) of which is short-circuited and the other end open, and the tip (12) of the straight portion (2) adjoining the cylindrical coil (6) is in contact with this lead (51).

Abstract: A dual traveling wave resonator filter includes a microstrip line to receive an input signal at a first end and first and second traveling wave resonator rings. Each traveling wave resonator ring is in close proximity to the microstrip line such that first and second resonant first combined signals are induced, respectively, in each of the first and second traveling wave resonator rings in response to the input signal on the microstrip line. A band-reject signal is rejected from the microstrip line and a pass-band signal is produced from the microstrip line at a second end.