Showing papers on "Waveguide filter published in 1987"

Dielectric High-Power Bandpass Filter Using Quarter-Cut TE/018/ Image Resonator for Cellular Base Stations

Abstract: A dielectric high-power bandpass filter using "quarter-cut TE/sub 01delta/ image resonators" has been developed. The resonator has a high unloaded Q over 7000 and its construction provides a sufficient thermal diffusion path to the metal housing. The insertion loss and the attenuation level of the eight-pole elliptic function type filter are 0.37 dB and 95 dB, respectively. The physical size of the dielectric filter is 280x135x 65 mm, one third to one fifth the volume of conventional cavity resonator filters.

Electro-optically tunable, narrowband Ti:LiNbO3 wavelength filter

Abstract: We report a tunable optical transmission filter for 1.5?n with a bandwidth of 12 A and a tuning range of at least 80 A. The filter is based on wavelength-dependent polarisation conversion in a birefringent waveguide and employs a periodic electrode structure with interleaved birefringence tuning electrodes.

Multiple resonator component-mountable filter

Abstract: A dielectric block filter (501) which may be mounted on a printed circuit board or other substrate as a single component. The dielectric filter utilizes metallized hole foreshortened resonators (529-535) in the dielectric block (501), which employs capacitive coupling between resonators controlled in part by an electrode strip (553-558) coupled to the conductive material covering the majority of the dielectric block (501) surface. Input and output coupling is accomplished via terminals (505-507) asymmetrically arranged in a mounting bracket (503). Mounting tabs (515-523) on the bracket (503) opposite a recessed area holding the dielectric block secure the filter (501) to the circuit board and provide ground connection for the filter. Two or more filters (501) may be arranged on the circuit board to form a duplexer.

Canonical Bandpass Filters Using Dual-Mode Dielectric Resonators

Abstract: A canonical bandpass filter constructed by placing dual-mode dielectric resonators coaxially in a cutoff circular waveguide is discussed Rigorous analysis of the dual-mode dielectric resonator and inter-resonator coupling is performed with the mode matching technique Four- and six-pole elliptic bandpass filters are realized at 12 GHz

Dual mode waveguide filter employing coupling element for asymmetric response.

Abstract: A dual mode circular-type waveguide filter (10) has a cylindrical waveguide body (12) separated by septums (16, 18) into a plurality of resonant waveguide cavities (22, 24, 26). Mutually orthogonal electromagnetic fields (37, 81) in adjacent cavities (24, 26) are electromagnetically coupled with each other by an internal coupling element (60) which is mounted on one of the septums (18) and extends into the adjacent cavities. The coupling element comprises an elongate, conductive wire which includes a first portion (62) extending into one of the cavities and forming a magnetic loop, and a second portion (64) extending into the adjacent cavity and forming an electric probe. The coupling element provides an asymmetrical stopband pole (72a) in the frequency response (70) of the filter.

Laser beam scanning using a local deflector integrated with an effective mode filter

Abstract: Deflection of a diode laser beam using an injection‐type deflector monolithically integrated with a very long waveguide is demonstrated. The deflector and the waveguide constitute a laser cavity. The waveguide filters out higher order modes, and only the fundamental‐mode light is incident on the deflector. Because the incident light is of a fixed single mode, the deflection of the output beam is very smooth. The deflection mechanism is primarily due to interference between constituent modes for short deflectors, and phase‐front tilting of each mode for long deflectors.

Waveguide Filter Tutorial.

Abstract: This tutorial was adapted from the conference paper “Waveguide Filter Tutorial,” by J.O. Smith, Proceedings of the International Computer Music Conference (ICMC-87), pp. 9–16, Champaign-Urbana, 1987, Computer Music Association.

A Unified Ridge Structure for Evanescent Mode Wideband Harmonic Filters: Analysis and Applications

Abstract: This paper present an accurate analysis of various applications of a double antipodal ridge waveguide structure which is loaded with different dielectric materials Design parameters, i.e. the cutofff frequencies of the TE10 and TE20 modes, equivalent dielectric constant, characteristic and gap impedances have been calculated. This versatile type of ridge structure can be considered a unified structure for evanescent-mode ridge waveguide lowpass and bandpass harmonic filters. A great deal of flexibility in the choice of size, power handling capability, out-of-band isolation, and bandwidth can be achieved. The accuracy of the analysis has been verified by the development of a widehand bandpass filter using evanescent mode serrated double antipodal ridge structure. Test results are provided.

Probe coupled waveguide multiplexer

Abstract: A probe coupled waveguide multiplexer (10) is provided including a first waveguide (12) which serves as a multiplexing manifold; a second waveguide (14), having a cavity (31), typically a filter, which is probe coupled to the first waveguide (12); and a third waveguide (20) which has a cavity and is probe coupled to the first waveguide such that the probe (17) of said third waveguide (20) is diametrically opposed to the probe (15) of said second waveguide (14) and the second and third waveguides (14, 20) are mounted in the same transverse plane in co-planar relation. The probe coupling method and apparatus disclosed herein allows the waveguide filters (14, 20) to be mounted on the manifold (12) in a close physical relation thereby minimizing the length of the manifold and associated costs.

Microwave multiband filter

Abstract: A multiband microwave filter that can selectively transmit a broadband signal or any discret or combination of predefined frequency bands. The filter has two transmission lines, with an output port at one end of a first one of the transmission lines. A switch selectively transmits an input signal to one of the transmission lines. The filter also has a plurality of narrowband directional filters, each of which is used to transmit signals in a corresonding frequency band from one of the transmission lines to the other. Each directional filter includes at least one diode for enabling and disabling the operation of the direction filter in accordance with a bias voltage applied to the diodes. By controlling the switch and applying appropriate bias voltages to each of the diodes, the microwave filter can selectively transmit a broadband signal or any discret or combination of the frequency bands transmitted by the directional filters.

Directional filter system

Abstract: A filter system is composed of two identical filters coupled between an input waveguide and an output waveguide to provide a 4-port directional filter characteristic operable with quasi-elliptic linear modes of electromagnetic propagation within each of the filters. Each of the filters may be constructed of a plurality of cavities arranged serially, one behind the other, with one of the cavities in each of the filters being employed for coupling electromagnetic power between the two waveguides. The coupling is accomplished by use of a transverse slot and a longitudinal slot in each of the waveguides, the slots extending through sidewalls of the waveguides into walls of the cavity in each of the filters for symmetric and antisymmetric coupling, respectively, of longitudinal and transverse components of a transverse electric wave in each of the waveguides. A phase quadrature relationship between components of a magnetic field coupled from the input waveguide is retained by the filters and, upon radiation via the slots into the output waveguide, results in the generation of an output wave in only one direction from the output waveguide, there being cancellation of a wave in the opposite direction from the output waveguide.

Launcher-less and lumped capacitor-less ceramic comb-line filters

Abstract: An inhomogeneous ceramic dielectric microwave RF TEM resonator filter having a plurality of unplated notches in the ceramic for enhancing direct inter-resonator coupling. The filter is implemented without the lumped coupling capacitors which are typically associated with each resonator of a TEM resonator filter. Furthermore, the launching resonators which are typically used to couple in and out of the filter are eliminated by using coaxial probe capacitors inserted in each of the end resonators. The non-end resonators can be made to look as long as the end resonators, with probes therein, by including a conductor pad disposed upon the block top surface and connecting the internal plating of the non-end resonators.

Analysis and Design of Evanescent Mode Waveguide Filter with Non-Touching E-Plane Fins

Abstract: The analysis and design of evanescent mode waveguide filters with non-touching E-plane fins are presented. The theoretical analysis is based on the generalized scattering matrix technique in conjunction with the spectral domain approach and mode matching method. The mesasured filter responses in Ka band (26.5-40.0 GHz) are in good agreement with those obtained by analysis.

A Bandpass Filter Using High-Q Dielectric Ring Resonators

Abstract: A Tchebyscheff bandpass filter constructed by placing high-Q TE/sub 01delta/ dielectric ring resonators coaxially in a TE/sub 01/ cutoff circular waveguide is designed precisely by the mode matching technique. Some discussions for design of the high-Q resonators and inter-resonator coupling are presented.

A Bandpass Filter Using Circular Discontinuities in Nonradiative Dielectric Waveguide

Abstract: The design of a new bandpass filter in Non-radiative Dielectric (NRD) Waveguide is described. The filter makes use of an inverter-prototype and series fullwave resonators. The T-sections necessary to realize the inverters are realized by means of round holes drilled through the dielectric centre conductor. The properties of the round discontinuities are fitted to those of rectangular holes, and the design is executed by means of closed form equations. The measured practical response is in very good agreement with the predicted theoretical properties.

Ferrite tunable metal insert filter

Abstract: A novel type of magnetically tunable waveguide filter is presented which is highly appropriate for E-plane integrated circuit applications. The design theory, which is based on the field expansion into normalised eigenmodes and the modal S-matrix description of the discontinuities, includes both higher-order mode interaction and finite thickness of the E-plane metal, as well as of the lateral ferrite inserts. Optimised design data for two-and three-resonator-type filters are given for midband frequencies of about 15.3-15.4 GHz and 14.1-14.8 GHz. The theory is verified by measurement

Photofabrication Of Multimode Network Components

Abstract: A low-cost two wavelength multi/demultiplexer was fabricated for multimode local area network applications in the transportation vehicle environment. Polymer optical waveguides, a Y-splitter, and intra waveguide filter were combined to form the optical circuit using photofabrication techniques amenable to mass production methodology. A 6 dB insertion loss was attained which was 3 dB greater than the expected 50/50 splitter loss.

Device for receiving high-frequency signal

Abstract: The device is composed of a rectangular waveguide filter made up with series resonator, a microstrip circuit and a microstrip superhigh frequency signal device for waveguide filtering which is connected with the said circuit. Since an appropriate spacing between frequency channels may be obtained by means of fitting a stripline of waveguide filter breakover and matched it with a waveguide filter in the filter, the receiving unit may be more smaller in dimensions than conventional one, a low reflecting factor may be achieved and it is unnecessary to regulate the breakover to the waveguide filter.

Low-loss and lightweight on-board 20 GHz-band pill-box-type directional filter

Abstract: An on-board channel multiplexer using pill-box-shaped TM310 travelling-wave cavities with high unloaded Q-factor has been developed in the 20 GHz band. The measured branching loss of a three-cavity filter is 0.27 dB at a resonant frequency of 19.99 GHz. The weight of the filter made of thin-walled super-Invar is 71 g. Its size is 4.5×4.6×5.1 cm.

Dielectric Resonator Wide Band Tuning Cavity for High Performance Filters

Abstract: Compared with the conventional waveguide filters the new type of dielectric resonator filters featured by special tuning screws and coupling in between the resonators through circular irises not only permits to reduce insertion losses, dimensions and cost, but also assures an improvement of the out-of-band spurious response, further miniaturizing of the structure and wide band tunability.

Two-Dimensional Synthesis and Design of MIC Filters

Abstract: Microstrip low-pass filters with very wide stopbands and very sharp cutoff rates have been designed and realized using a new technique which incorporates two-dimensional effects in the synthesis procedure. This removes the limitations inherent to the conventional transmission line approach and makes the present one particularly suited for monolithic microwave circuits.

A 93 GHz Circumferential Waveguide Bandpass Filter with Broad Bandwidth and Low Loss

Abstract: A new waveguide band-pass filter has been developed and realized for W-band. It differs significantly from traditional microwave filters at lower frequencies subsequent upon a very simple arrangement which is well-suited for milled splitblock waveguide design. The band-pass filter consists of a circumferential waveguide section with three rotationally symmetrical feeding arms. One of them includes a slide which shorts the waveguide ring and thus cuts it into two halves. Consequently, the layout represents two short- and one open-circuited resonance lines. A bandwidth of more than 10 per cent and an insertion loss of typically 1 dB have been measured at a center frequency of 93 GHz.