Abstract: The tunable filters of the present invention incorporate tunable dielectric materials (e.g., bulk and thin film ferroelectric and paraelectric materials) in contact with segments of resonators that are at an RF voltage maximum to alter the pass band or stop band characteristic of an RF signal outputted by the filter. The biasing circuitry in contact with the tunable dielectric material can include components for inhibiting or retarding the coupling of RF energy to the biasing circuit.

Abstract: In a magnetically-tunable resonator, a wave-guiding structure comprising an electromagnetic frequency filter, or component of such a filter, is placed in sufficient proximity with a magnetic structure so as to be gyromagnetically coupled therewith. The resonator is supportable of two fundamental normal modes of propagation which, in the absence of magnetic interaction are even and odd with respect to the resonator center plane of symmetry. Each normal mode possesses a spectrum of resonance frequencies. When the magnetic structure is magnetized, the formerly even and odd modes become mixed due to gyromagnetic interaction, and the resulting wave fields become elliptically polarized. With appropriate design such that the identities of the modes are preserved under conditions of resonance, this in turn results in a nonreciprocal reinforcement action in the resonator, which leads to the desired shift in resonance frequency in at least one of the two normal modes.

Abstract: This invention pertains to monolithic filters of the band-pass or band-reject type which a single crystal ferroelectric material having an electric field dependent permittivity. The filters are comprised of: a first layer of a single crystal dielectric material; a second layer of a single crystal high T.sub.c superconductor material; a third layer of a single crystal ferroelectric material; and a fourth layer of high T.sub.c superconductive microstrip lines configured into the various filter circuits, including resonator circuits and transformer circuits. The filters are capable of operating at power levels up to 0.5 MW at a temperature slightly above the Curie temperature to avoid hysteresis.

Abstract: A high frequency filter includes a dielectric plate 8, an outer conductor 9 formed on the one surface of the dielectric plate 8, a plurality of strip conductors 10a-10d formed approximately in parallel on the other surface of the dielectric plate 8, a strip conductor 15 formed in a direction crossing the strip conductors 10a-10d, short-circuiting portions 11 and 16 connecting the one ends of the strip conductors 10a-10d and the strip conductor to the outer conductor 9, respectively, and further comprises a plurality of resonators 110a-110d constructed by the strip conductors 10, a plurality of capacitors (gaps) 12 coupling the resonators to each other to be connected in series, capacitors 13 connecting the strip conductors 10a, 10d to an input terminal and an outer conductor, respectively, a resonator 200 constructed by the strip conductor 15, and a plurality of capacitors (gaps) 33 connecting the strip conductors 10a, 10d to the resonator 200.

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 main CPW structure is formed by depositing two parallel films of a conductor on a film of a single crystal ferroelectric material. Cavities are formed by placing irises in a main CPW structure. These cavities are tuned to a dominant resonant frequency. By the application of a bias voltage to the main CPW structure with cavities, the permittivity of the film of the ferroelectric material, underneath the CPW structure, is changed. Thus the dominant resonant frequency of the filter is changed. By changing the level of the bias voltages, different dominant resonant frequencies of the filter are obtained. Thus a tunable band pass filter is obtained. With branch cavities on a CPW structure deposited on a ferroelectric film, a tunable band reject filter is obtained.

Abstract: A main symmetrical CPW structure is formed by depositing three parallel films of a conductor on a film of a single crystal ferroelectric material. Cavities are formed by placing irises in a main CPW structure. These cavities are tuned to a dominant resonant frequency. By the application of a bias voltage to the main CPW structure with cavities, the permittivity of the film of the ferroelectric material, underneath the CPW structure, is changed. Thus the dominant resonant frequency of the filter is changed. By changing the level of the bias voltages, different dominant resonant frequencies of the filter are obtained. Thus a tunable band pass filter is obtained. With branch cavities on a CPW structure deposited on a ferroelectric film, a tunable band reject filter is obtained.

Abstract: A desired frequency response of a microwave network on a monolithic microwave integrated circuit (MMIC), a microwave integrated circuit (MIC), or a hybrid circuit is achieved by selectively switching MEM switches to change the network topology. In a filter network, MEM switches connected between capacitors and inductors are selectively switched to change the network configuration to achieve a desired frequency response. In an amplifier network, the MEM switches are selectively switched to tune the amplifier to a desired frequency response and to reduce harmonic output.

Abstract: A microstripline resonator in which a desirable resonant frequency can be adjusted with less deterioration in Q and less production process steps is characterized in that a hollowed-out portion is formed in an electrode portion provided on an insulating substrate base. A width-narrowed portion is provided between the side edge of the electrode portion and the hollowed-out portion for adjusting the resonant frequency of the microstripline resonator.

Abstract: Quasi-stripline filters (20) are tuned during manufacture to achieve consistent frequency response. A filter structure (20) which accommodates the method (60) is provided. The microstrip filters (30) are fabricated by forming conductive filter patterns (22) upon non-conductive (dielectric) substrates (24), and then bonding those substrates (24) to conductive (metallic) substrates (28). These filters (30) are then entunneled with conductive housings (34) electrically and physically joined to the conductive plates (28). Housings (34) of varying cross-sectional areas (40) are chosen to produce the desired frequency response, thus converting the microstrip filters (30) into quasi-stripline filters (20) with a specific frequency response.

Abstract: The superconductor bandpass filter for electromagnetic signals includes a substrate (5); striplines (1) made of a type II superconductive material arranged on the substrate and a tuning device (2) for tuning the superconductor bandpass filter consisting of a device for changing a magnetic penetration depth .lambda.(T) of the striplines (1), so as to change the effective length, effective width and effective spacing of the striplines and thus to change the center frequency and/or the bandwidth. The device for changing the magnetic penetration depth .lambda.(T) of the striplines (1) advantageously includes a device for exerting a mechanical force or stress on the striplines and/or a device for varying a magnetic field applied to the striplines.

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 high-frequency circuit device includes a varactor diode having a first terminal and a second terminal, a first strip line connected to the first terminal of the varactor diode, a voltage being applied to the varactor diode via the first terminal, a second strip line having a first end connected to the second terminal of the varactor diode, and a second open end. The second strip line has a length so as to obtain an equivalent strip line length taking into capacitances of the varactor diode and the second strip line. The equivalent strip line length determines a characteristic of the high-frequency circuit device.

Abstract: A MMIC high Tc superconducting ferroelectric phase shifter is comprised of as microstrip line on a film of a single crystal ferroelectric material. To operate the phase shifter over a desired bandwidth a quadrature band pass filter, having 1,2,3, . . . coupled lines, is coupled to the phase shifter. The microstrip lines are comprised of a high Tc superconductor such as YBCO, TBCCO.

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: Strip line filter, receiver with strip line filter and method of tuning the strip line filter. In ceramic filters for frequencies from 1 to 2 GHz, strip line resonators lying in one plane and coupled via the side are currently used in the state of the art. For reducing the attenuating effect of such a filter in the passband, the strip line resonators are arranged in two different planes and coupled via the broad side.

Abstract: A plurality of dielectric sheets are laminated and bonded together to constitute a laminated board. A plurality of strip-shaped resonance electrodes are formed in parallel on a predetermined bonding face of the dielectric sheets, and the strip-shaped resonance electrodes reach opposite edges of the laminated board. Recesses are formed by locally cutting out the portions of the edges of the laminated board in which the respective resonance electrodes are exposed at their particular ends. Grounding electrodes are respectively formed on the obverse and reverse faces of the laminated board, and edge grounding electrodes are formed in the portions of the opposite edges of the laminated board except for the recess.

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 bandpass filter comprises multiple side-coupled strip line resonators wherein the resonators are staggered or offset with respect to their nearest neighbors by substantially 1/4 wavelength or less. In the preferred embodiment, the strip line bandpass filter structure has substantially parallel resonators arrayed with substantially constant spacing between the resonators with 1/4 wavelength overlap or less. Generally, the amount of stagger between nearest neighbors is reduced for resonators toward the center of the filter. Coupling between resonators is controlled by varying the relative amount of stagger between resonators. The resonators may be formed from normal metal or superconducting materials, such as YBCO or thallium containing superconductors. A strip line structure may be formed by utilizing two mirror structures each comprising a substrate having a ground plane and a patterned staggered resonator array formed on the substrate on a side opposite the ground plane.

Abstract: The present invention discloses a frequency tunable filter which includes an electromagnetic (E-M) wave propagation line which includes a microstrip and a ground plane in the substrate for transmitting a sequence of E-M signals via the propagation line. The E-M wave propagation line includes a frequency tuning mechanism, i.e., the magnetic layer, which is capable of utilizing a ferromagnetic anti-resonance frequency response to the E-M signals transmitted via the propagation line for controlling and frequency tuning the E-M signal transmission. In one of the preferred embodiments, the E-M wave propagation line includes a microstrip forming on the top surface of a dielectric or semiconductor substrate for receiving and transmitting the E-M signals and a ground plane forming on the bottom surface of the semiconductor substrate. And, the frequency tuning mechanism includes a ferromagnetic layer formed in the substrate between the microstrip and the ground plane.

Abstract: A transmission line filter comprises four resonators (100, 200, 300, 400), and transmission zeroes can be added to the transfer function of the filter using a known phasing coupling technique using a transmission line (53, 54) coupled between two resonators. The location of the transmission zeroes can be varied using control circuits (A,B). Each control circuit comprises a series coupled inductance (55, 58) and capacitance (56, 59) forming a resonance circuit, the resonance frequency of which can be varied using a variable d.c. voltage (V.sub.1, V.sub.2). The inductance of each control circuit is arranged adjacent its respective transmission line so that the two are weakly electromagnetically coupled. By supplying the variable voltage to the resonance circuits, normal operation of the phasing coupling is affected, thereby varying the location of the transmission zero. One or more control circuits can be provided for filters having transmission zeroes in their transfer function which need to be varied.

Abstract: The design of a high Tc superconducting band reject tunable ferroelectric filter (TFF) is presented. The band reject TFF consists of a main microstrip line on a dielectric substrate. One or more half wavelength microstrip resonators, on a ferroelectric substrate, is coupled to the main microstrip line. At a resonant frequency of a resonator, a short circuit is presented on the main microstrip line resulting in a rejection of signal of that frequency. By applying a bias voltage to a resonator, the frequency of the resonator and, as such, the reject band of the filter is changed. Different resonators can be tuned to different frequencies.

Abstract: The design of a high Tc superconducting band pass tunable ferroelectric filter (TFF) is presented. The band pass TFF consists of an edge coupled filter on a ferroelectric substrate. Each input and output microstrip line is a quarter wavelength long. Each intermediate microstrip line is a half wavelength long with the first quarter wavelength being coupled to the preceding microstrip line and the remaining quarter wavelength being coupled to the succeeding microstrip line. Each microstrip line is connected, through an LC filter, to a common bias voltage source. Application of a bias voltage changes the frequency of operation of the filter. For matching the impedances of the input and output of the filter to the impedances of an input and output circuit respectively, matching ferroelectric quarter wavelength transformers are provided.

Abstract: A port selection circuit in which a port selection section and a variable frequency filter are integrated on a substrate. The port selection circuit selectively connects any one of first to n-th ports to an (n+1)-th port and comprises first to n-th switches. Each of the switches includes one end connected to a corresponding one of the first to n-th ports and the other end connected to a common connecting point. When any one of the first to n-th ports is selected, a variable frequency filter connected between the common connecting point and the (n+1)-th port is set to a frequency characteristic for transmitting the frequency assigned to the selected port.

Abstract: A compact, high performance strip line filter which may be made thinner than a dielectric filter having comparable performance characteristics. The strip line filter includes a rectangular box-shaped, dielectric block having parallel grooves, formed in a front face with a predetermined spacing therebetween, the grooves extending from a top face to a bottom face of the block. A thin film outer conductive layer covers the side faces, the back face, and the bottom face. Resonator conductors, each formed of a thin film of conductive material, cover the respective surfaces of the grooves and are connected to the outer conductor. According to a further aspect, a substrate, with capacitor formed thereon, opposes a face of the dielectric block to provide capacitive coupling. The capacitors may be arranged to provide attenuation poles at finite frequencies. In accordance with another aspect, such strip line filters are used as the transmitting and receiving filters of a duplexer filter.

Abstract: A voltage-controlled microwave oscillator having a field effect transistor (1) as an amplifier and having a varactor diode (2) as a frequency-determining element has high output power and a large enough frequency sweep in the microwave frequency range that S-parameter scatters of the active components have optimally little influence on the characteristic data of the oscillator. The varactor diode (2) is preceded by a tunable micro stripline filter (3) and the source electrode of the field effect transistor (1) is directly connected to ground in order to form a parallel feedback with the micro stripline filter (3).

Abstract: A planar, magnetically-tunable, band-rejection filter comprising a slot-l having at least one magnetically tunable, dielectric resonator-stack positioned on its top surface. The core of each resonator stack is filled with ferrite material. As a result, the filter provides a higher "Q", and thus provides greater suppression of unwanted microwave and millimeter-wave signals than the prior art.

Abstract: A tunable microwave bandstop filter device comprises a main microwave transmission line (1), at least one filter cell comprising a coupled line segment (4) coupled to the main transmission line (1) and arranged parallel to and remotely from the latter, and also a tunable LC resonant circuit (5, 6). According to the invention, the tunable LC resonant circuit (5, 6) is placed between one of the ends of the line segment (4) and the main microwave transmission line (1).

Abstract: A planar preselector filter with tunable narrowband excision composed of a errite substrate having a microstrip line with a fixed-tuned bandpass filter on one surface and a plurality of slotline resonators etched in a ground plane on an opposing surface. The fixed tuned bandpass filter is composed of short resonant elements of microstrip, having a length that is one-half the guide wavelength at the center frequency of its passband. The slotline resonators are positioned on the opposing surface of the substrate such that it suppresses or excises a predetermined narrowband of frequencies within the passband of the fixed-tuned bandpass filter. Moreover, the center frequency of the narrowband excision is varied by applying a tunable magnetic bias field of a predetermined strength across the ferrite substrate.

Abstract: A tri-plate type dielectric filter having a dielectric substrate, a plurality of resonator electrodes embedded in the substrate, and coupling electrodes formed within the dielectric substrate for capacitively connecting the resonator electrodes to provide capacitors between adjacent resonator electrodes. The resonator electrodes may take the form of parallel elongate strips each providing a stripline type .lambda./4 or .lambda./2 TEM mode resonance circuit. One end of each strip is exposed at an outer surface of the substrate. This end of each strip is trimmed to adjust the resonance frequency of the resonance circuit.

Abstract: A microstrip filter having a plurality of parallel resonant conductors mounted on a dielectric substrate is tuned by applying a portion of a hot-melt type glue to the filter surface. The glue is melted and then deposited on the conductors and spread across and along the conductors until the filter has a desired frequency response. The glue is then cooled until it becomes solid.

Abstract: A stripline filter device including two or more dielectric substrate assemblies each having a pair of superimposed dielectric substrates between which at least one resonator conductor is disposed, wherein the dielectric substrate assemblies are stacked with an intermediate dielectric layer being sandwiched between the adjacent substrate assemblies so as to couple the resonator conductors in a direction perpendicular to the plane of each substrate, and by suitably setting the material and/or the thickness of each intermediate dielectric layer the coupling quantity between the resonators can be adjusted to obtain a desired frequency bandwidth.

Abstract: A tri-plate type dielectric filter having a dielectric substrate, a plurality of resonator electrodes embedded in the substrate, and coupling electrodes formed within the dielectric substrate for capacitively connecting the resonator electrodes to provide capacitors between adjacent resonator electrodes. The resonator electrodes may take the form of parallel elongate strips each providing a stripline type .lambda./4 or .lambda./2 TEM mode resonance circuit. One end of each strip is exposed at an outer surface of the substrate. This end of each strip is trimmed to adjust the resonance frequency of the resonance circuit.

Abstract: A radio frequency transmission line filter has an insulative substrate substantially in the form of a plate of dielectric material, a ground plane formed by metallization on one face of the substrate, capacitor plates formed by areas of metallization on the other face of the substrate to form, in conjunction with the ground plane, capacitances, and coupled to the capacitances, respective metallized short circuit transmission line stubs forming inductances. The inductances and capacitances together form transmission line resonators. To allow the designer a wide choice in capacitance and/or inductance values, the substrate is recessed in selected areas to bring the ground plane to within predetermined distances of the capacitor plates or inductance stubs. The ground plane may be trimmed in the recessed areas to adjust component values.

Abstract: Disclosed is a TEM mode resonator having as a means for adjusting the resonance frequency a simple frequency adjusting mechanism appropriate for size reduction while permitting easy mounting of a varactor diode for varying the resonance frequency thereto. Below a strip transmission line 2 is provided a slot 7 having a length L perpendicular to the transmission line as located at an outer ground conductor surface 3 of a one-fourth wavelength type microstrip line resonator having its one end short-circuited. According as increasing the slot length L, the resonance frequency of the resonator reduces, which characteristic is utilized as a means for adjusting the resonance frequency. By connecting a varactor diode at a center portion of the slot line and varying the voltage applied to the diode, the resonance frequency can be varied.

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: The present invention discloses a method for manufacturing a high dielectric antenna structure. In one embodiment, one or more high dielectric film layers are applied to a dielectric base layer by silk-screening to yield a dielectric structure having a dielectric constant greater than that of the dielectric base layer. After firing, a patch antenna element having a predetermined configuration is disposed on the top surface of the dielectric structure by silk-screening a conductive paste thereupon and firing. A ground plane is disposed on the bottom surface of the dielectric structure by silk-screening a conductive paste thereupon and firing. A pre-drilled dielectric base layer may be employed with registered holes defined in the various silk-screened layers to provide access for an RF feed means, or alternatively, a feed hole can be bored through the antenna structure to permit interconnection between an RF feed means and the patch antenna element.

Abstract: A tri-plate line is constructed from a resonance element formed by intervening dielectrics between one pair of ground conductors (6). The length of the line is adjusted to about 1/4 wave-length. Then, a bandpass filter is formed by combining a plurality of resonators (5) of which one end is grounded. Each of the resonators (5) is separated by separators (9) so that waveguide mode propagation in the tri-plate line is prevented from occurring. A plurality of the tri-plate lines are piled up. The electromagnetic coupling of the resonators in different layers with each other are conducted by means of coupling means (7) formed in the dielectric and the ground conductor. The resonators disposed at both ends are coupled with input/output terminals (1,2), respectively.

Abstract: A planar tunable YIG filter assembly comprising a first substrate having on one side thereof spaced ridges, a first conductor spaced from and between the ridges, a dielectric spacer and YIG disk is mounted on said spacer whereby, a bandpass filter is established between said first conductor and a second conductor that is orthogonal with said first conductor and on a second substrate that is in contact with the ridges when means are provided for producing a magnetic field that is perpendicular to the substrate in the area of intersection of the first and second conductors.

Abstract: A method of adjusting a frequency response in a filter device of a three-conductor type having a pair of stacked dielectric substrates with a plurality of strip-line resonator conductors being sandwiched therebetween, wherein the frequency adjusting of the filter is performed by partially removing the external ground conductor layer on the peripheral surface of each substrate at a region corresponding to a longitudinal side edge of each resonator conductor layer.

Abstract: A low loss, fast switching, electronically tunable filter circuit which is microstrip compatible is obtained through the use of a resonant ring structure having two couplers, a low noise amplifier and a variable phase shifter. The tunable filter may advantageously be used in the receive channel of a transmit/receive module for phased arrays wherein the resonant frequency of the ring can be tuned anywhere in the operating frequency range so as to increase the dynamic range of the receiver.

Abstract: A method of adjusting a frequency response in a stripline filter device having a pair of stacked dielectric substrates with a plurality of stripline resonator conductors being sandwiched therebetween, wherein the frequency adjusting of the filter is performed by partially exposing the open circuit end of each of the resonator electrodes or a filamentary conductor for connecting the open end to the ground conducting layer on the outer surface of one of the dielectric substrates and then partially removing the partially exposed open circuit end of each resonator electrode or the partially exposed filamentary conductor connected to the open circuit end.

Abstract: A transmission line structure (100) is provided which includes a resonator (110) having open ends (118) disposed on a substrate (130). The first resonator (110) includes a control voltage terminal (116) which is positioned at a point along the length where a zero potential exists at resonant frequency. Transmission zero frequency is tuned by means of a varactor (150) which is coupled to the control voltage terminal and receives a control voltage for controlling the zero frequency.

Abstract: In order to efficiently and steadily remove a frequency-fluctuating interference wave, for instance, a leakage wave of a household electronic oven, intermixed into a received wave for communication, adaptively to the frequency deviation and the frequency fluctuation of the interference wave, a rejection band component included in the received wave applied onto a circulator, an output terminal of which is connected with a variable band rejection filter, is reflected from the output terminal on which impedance mismatch is caused by zero-impedance presented by the rejection filter on the basis of absorption of the input wave and applied to a detector through the circulator again, in response to a detection output of which a so-called peak-keeping control is effected on the variable band rejection filter for shifting the rejection band, so as to maximize the detection output of the detector adaptively to the frequency deviation and the frequency fluctuation of the interference wave.

Abstract: A first dielectric block or blocks have a cut out portion and the cut out space is filled with a second dielectric block. A bypass pattern is formed on the second dielectric block and is capacitively coupled with two resonance elements formed on the first dielectric block or blocks. the dielectric filter is compact, and the position and intensity of attenuation poles can be freely designed and easily adjusted.

Abstract: A dielectric resonator has a pattern of metallic micro-wave strips deposited onto a dielectric substrate having a high relative permittivity. The pattern is of a generally annular shape and has a slot formed in the annular pattern. The resonator includes an positive feedback circuit coupled thereto having an active element, such as a transistor, and is usable, for instance, as a band-cut off or band-pass filter.

Abstract: A miniature, electrostatically actuated, stub tuner which is operable to dynamically tune a transmission line in response to control signals. With the use of integrated circuit processing the transmission line is fabricated on a substrate and at least one stub tuner is fabricated over the substrate and is movable relative to the transmission line in response to electrostatic fields produced when the control signals are selectively applied to rows of control electrodes.

Abstract: A transmission line filter is provided which includes a first resonator having open ends being coupled to a second resonator disposed on a substrate. A transmission zero frequency is tuned by means of a varactor which is coupled between the first and the second resonator. The first resonator includes a terminal for applying a control voltage to the varactor for varying its capacitance.

Abstract: A high-frequency band-pass filter has an input resonator, a middle resonator and an output resonator which are coupled in parallel. The input resonator and the output resonator are capacitively shortened quarter-wave line resonators. To improve the attenuation characteristics, the middle resonator is designed as a capacitively shortened half-wave resonator. The input resonator extends along a first part of the length of the middle resonator. The output resonator extends along a second part of the length of the middle resonator.

Abstract: An improved stripline filter is disclosed which includes a laminate of a pair of dielectric substrates each having an outer surface provided with a ground conductor, and conducting resonator means provided between each of the two adjacent dielectric substrates and having a plurality of parallel resonator fingers each having an open circuit end and a base end electrically connected to said ground conductor, in which the ground conductor has extended portions corresponding in number to the number of the resonator fingers, each of the extended portions extending toward the open circuit end of the corresponding resonator finger and terminating with a predetermined space from the open circuit end of the corresponding resonator finger.