Abstract: A reflective waveguide variable power divider/combiner comprises an orthomode tee section, which includes a section of cylindrical waveguide and a rotatable reflective phase shifter section. The rotatable reflective phase shifter section is rotatably connected to the orthomode tee section by a cylindrical choke joint. The orthomode tee section includes a single orthomode tee unit. The reflective waveguide variable power divider/combiner terminates at a short circuit that separates a motor from the rotatable reflective phase shifter section. The motor is configured to rotate the rotatable reflective phase shifter section relative to the orthomode tee section.

Abstract: A capacitive coupler for a microwave circuit that has a first cavity and a second cavity separated by a wall. The separating wall has an aperture that, due to its shape, is capacitive. The aperture has a pair of elongated walls separated by a pair of side walls. The elongated walls and the side walls each have a thickness substantially thicker than what is now the industry standard. At least one of the elongated walls has a ridge. Because the distance between the first elongated wall and the second elongated wall is substantially greater than that previously known, the aperture may be easily manufactured.

Abstract: An electromagnetic resonator comprises a waveguide body having a generally tubular side wall and a pair of end wall assemblies. The end wall assembly includes a bowed aluminum plate and an INVAR disk, attached to one another at the periphery thereof. The INVAR disk includes a relatively thick outer annular portion and a relatively thin inner circular portion. The bowed aluminum plate bows in response to increased temperature, thereby counteracting expansion of the waveguide body.

Abstract: A coaxial "M" switch having three coaxial input connectors (A, B, C) spaced evenly from each other, and three coaxial output connectors (1, 2, 3) identically arranged. In a cylindrical barrel embodiment (10) the input and output connectors are located at opposite ends of a cylindrical configuration. In one planar embodiment (30), the input and output connectors alternate with each other and define a hexagonal configuration (40). In another planar embodiment, the input connectors (A, B, C) define an inner triangular configuration (70) that is surrounded by the output connectors (1, 2, 3) defining an outer triangular configuration. In each embodiment, reeds are actuated in predetermined configurations to define three switch positions.

Abstract: An electromagnetic resonator comprises an interior wall defining a substantially cylindrical cavity having a major axis. The interior wall includes first and second coupling grooves substantially parallel to the major axis. For a lesser level of coupling, the coupling grooves may be shorter than the length of the resonator and/or the second coupling groove may be omitted.

Abstract: The present invention discloses a microwave filter (10) for controlling the degenerate resonant modes of a spherical cavity resonator (12). The spherical cavity resonator (12) has an inner spherical surface (14) which defines a spherical cavity (16). A first and a second set of tuning elements (18) extend inward from the inner spherical surface (14) of the resonator (12) into the spherical cavity (16). One of the first set of tuning elements is located near an electromagnetic field peak, either a radial electric field peak or a surface magnetic field peak, of at least one of the degenerate modes for tuning a resonance thereof. One of the second set of tuning elements is located between electromagnetic field peaks, either radial electric or surface magnetic field peaks, of degenerate modes in at least one pair of the degenerate modes for intercoupling thereof.

Abstract: A bandpass microwave filter (32) is constructed by use of a right cylindrical cavity resonator (10) wherein end regions (22, 24) of the resonator are tapered. The tapering is accomplished by replacing end portions of a right cylindrical sidewall with frusto-conic sections (22, 24) of side wall. Each frusto-conic section joins a central cylindrical section (26) of the sidewall with a planar end wall (14, 16). Each of the end walls is provided with a coupling slot (28, 30) having dimensions substantially smaller than a half wavelength of the center resonant frequency of the resonator so as to be a nonresonant slot. The slots in the end walls may be coupled to rectangular waveguides (34, 36) which form input and output ports by which electromagnetic signals are applied to and extracted from the resonator.

Abstract: A power divider (20) includes two orthomode tee to cylindrical waveguide adapters (26, 34) coupled by a phase shift unit (48) having a slow-wave structure (68) located in a sidewall (82) of a waveguide section (50) at a position located 45 degrees between planes of rectangular ports of the adapters. The slow-wave structure includes a set of vanes (54) which are movable by means of a motor (58) to adjust their penetration through the sidewall of the waveguide section. Adjustment of the penetration provides for selection of an amount of differential phase lag introduced between components of electromagnetic waves propagating through the waveguide section between the two adapters. Pins (96) are formed integrally with the vanes by a notching of edge regions of the vanes. The pins introduce a relatively small amount of phase shift as compared to that introduced by the vanes. However, the phase dispersion of the pins counteracts a phase dispersion of the vanes for increased bandwidth of the power divider.

Abstract: A plural cavity structure (10), suitable for use as a microwave filter (34, 34A, 34B) , has plural cavities (24, 26, 28, 30) disposed within a cylindrical aluminum housing (12) and having a central planar transverse wall (18) including an iris (38) for coupling of electromagnetic power between two successive ones of the cavities (28, 26). The transverse walls are bowed, and peripheral regions of the walls are clamped by metallic rings (66, 68, 70, 72) differing in their coefficients of thermal expansion. Thus, the rings (68, 70) of the inboard transverse walls (16, 20) are formed of titanium having a relatively high coefficient of thermal expansion, while the rings (66, 72) of the outboard transverse walls (14, 22) are formed of INVAR having a relatively low coefficient of thermal expansion.

Abstract: A non-contacting waveguide "T" switch (10) is provided including a stator (12), a rotor (14) mounted for rotation relative to the stator, and a coaxial conductor (64) located at the axis of the rotor for carrying a coaxial transmission. The stator (12) has at least one waveguide port (32). The rotor (14) includes a through-waveguide (48) and an impedance matching transformer (52) disposed in the through-waveguide (48) for converting the coaxial transmission into a waveguide transmission. The transformer (52) has a bore which forms a non-contacting sleeve about the coaxial conductor (64). The through-waveguide (48) carries the waveguide transmission radiated from the transformer to the at least one waveguide port (32).

Abstract: A switchable dual mode directional filter system includes two identical filters coupled to input and output waveguides at the same plane in phase quadrature. Each waveguide has two ports through which the signal enters and exists. One of the filters has a switching device incorporated therein for selecting the desired output port. One embodiment of the switching device includes a pair of coupling members that extend radially inward within the cavity of the filter toward a central axis. These coupling members define two coupling positions for the system. Solenoids move the two coupling members into and out of the cavity of the filters. Only one coupling member is used at a given time. This switching device is designed to change the polarity of one of the components of the signal wave to change its wave characteristics in the output waveguide. As a result, the desired port of the output waveguide can be selected easily.

Abstract: An iris for an electromagnetic structure, such as a resonator assembly, is provided with a set of grooves introducing relief to thermally induced stresses, this allowing the iris to be fabricated of a metal having a greater coefficient of thermal expansion than the material of a sidewall and end walls of the resonator assembly. The grooves are arranged spaced apart from the central coupling aperture, and are disposed in an annular region of the iris plate composing the central coupling aperture. The grooves may be cut into the iris plate from both sides of the plate to extend partway into the plate, typically, approximately three-quarters of the distance through the plate. Alternatively, the grooves may pass completely through the plate, whereupon annular disks are soldered to the opposite sides of the iris plate to close off the grooves to ensure that coupling of electromagnetic power between opposite sides of the iris takes place only through the coupling aperture.

Abstract: A microwave band pass filter for filtering electromagnetic signals has a set of cavities arranged serially, with a block of dielectric material filling each cavity to define regions of each cavity which are loaded with dielectric material and regions which are free of the dielectric material. Each cavity may be viewed as a resonator for a fundamental mode of progagation of an electromagnetic wave while each block can be viewed as a resonator for higher-order modes of propagation of electromagnetic power. The cavities are separated by walls having slots aligned with the free regions of the cavities for coupling power from the fundamental mode while minimizing interaction with power of the higher-order modes. The filter enables the construction of an enlarged passband while inhibiting the presence of the spurious higher-order modes in a stop band bordering the passband.

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.

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

Abstract: A microwave resonator is disclosed which includes a temperature-compensating structure within the resonator cavity configured to undergo temperature-induced dimensional changes which substantially minimize the resonant frequency change otherwise caused by temperature-induced changes in the waveguide body cavity. The temperature-compensating structure includes both bowed and cantilevered structures on the cavity endwall, as well as structures on the cavity sidewall such as a tuning screw of temperature-responsive varying diameter.