Abstract: A quasi-lumped resonator apparatus that makes use of an inductive portion having a plurality of spines extending therefrom along at least a portion of a length thereof, and a capacitive portion electrically and physically coupled to an end of the inductive portion. The capacitive portion has a plurality of spaced apart capacitive fringe plates extending therefrom. A housing is included for enclosing the inductive and capacitive portions. In another aspect a method is disclosed for forming a quasi-lumped resonator.

Abstract: Systems and methods are disclosed herein to provide improved phased array antenna system. For example, in accordance with an embodiment of the present invention, a phased array antenna system includes a plurality of horn/filter assemblies. A plurality of modules are adapted to provide RF signals to the horn/filter assemblies. Each of the horn/filter assemblies is mounted on a top surface of a corresponding one of the modules. A thermal system is adapted to cool the modules. The modules are mounted on a first surface of the thermal system. A plurality of distribution boards associated with the modules are mounted on a second surface of the thermal system. A plurality of interconnects associated with the modules are adapted to connect the modules with the distribution boards through the thermal system.

Abstract: Systems and methods are disclosed herein to provide improved phased array antenna system. For example, in accordance with an embodiment of the present invention, a phased array antenna system includes a plurality of horn/filter assemblies. A plurality of modules are adapted to provide RF signals to the horn/filter assemblies. Each of the horn/filter assemblies is mounted on a top surface of a corresponding one of the modules. A thermal system is adapted to cool the modules. The modules are mounted on a first surface of the thermal system. A plurality of distribution boards associated with the modules are mounted on a second surface of the thermal system. A plurality of interconnects associated with the modules are adapted to connect the modules with the distribution boards through the thermal system.

Abstract: A microwave waveguide filter includes a main-line cavity structure with a group of at least two rectangular main-line cavities arrayed along a main propagation path and including a first main-line cavity and a second main-line cavity. Each main-line cavity includes a sidewall, and each pair of adjacent main-line cavities has a common transverse wall transverse to the main propagation path and a main-line aperture in the common transverse wall. A rectangular first feedback cavity is in microwave communication with each of the first main-line cavity and the second main-line cavity through the respective sidewall of the first main-line cavity and the second main-line cavity. There is a first-cavity feedback aperture between the first feedback cavity and the first main-line cavity, and a second-cavity feedback aperture between the first feedback cavity and the second main-line cavity. There may be additional feedback cavities as well.

Abstract: A microwave waveguide filter includes a main-line cavity structure with a group of at least two rectangular main-line cavities arrayed along a main propagation path and including a first main-line cavity and a second main-line cavity. Each main-line cavity includes a sidewall, and each pair of adjacent main-line cavities has a common transverse wall transverse to the main propagation path and a main-line aperture in the common transverse wall. A rectangular first feedback cavity is in microwave communication with each of the first main-line cavity and the second main-line cavity through the respective sidewall of the first main-line cavity and the second main-line cavity. There is a first-cavity feedback aperture between the first feedback cavity and the first main-line cavity, and a second-cavity feedback aperture between the first feedback cavity and the second main-line cavity. There may be additional feedback cavities as well.

Abstract: An improved stepped-impedance low pass filter includes a stepped-impedance low pass filter having at least one electrically conductive transmission line, such as a parallel plate, coaxial, or two-wire transmission line, having at least one inductive element and at least one capacitive element. The capacitive elements and the inductive elements are disposed in an alternating manner along a length of the transmission line. The resonance suppressed stepped-impedance low pass filter also includes at least one electrically conductive suppression element disposed along the inductive elements of the stepped-impedance low pass filter, such as centered along the inductive elements between pairs of capacitive elements. The suppression elements suppress a spurious response at at least one resonant frequency.

Abstract: A cavity-coupled microwave filter that uses TE011 and TE01&dgr; mode resonators. The cavity-coupled microwave filter includes an input port, a first resonator having a first opening, wherein the first opening receives electromagnetic energy from the input port, a second resonator having a second opening, wherein the second opening receives electromagnetic energy from the input port and wherein the first resonator and the second resonator are electromagnetically coupled. The cavity-coupled microwave filter further includes an output port, a third resonator having a third opening, wherein the third opening transfers electromagnetic energy to the output port and wherein the second resonator and the third resonator are electromagnetically coupled and a fourth resonator having a fourth opening, wherein the fourth opening transfers electromagnetic energy to the output port and wherein the third resonator and the fourth resonator are electromagnetically coupled.

Abstract: The present invention is directed to improved coupling mechanisms for TE.sub.011 and TE.sub.01.delta. mode resonators. In one embodiment, the coupling mechanism provides an adjustable connection for transferring electromagnetic energy from a first resonator to a second resonator. Once the resonators are coupled, the coupling mechanism is adapted to allow adjustment of the magnitude and/or the phase of the electromagnetic energy while preserving the electromagnetic connection between the resonators. In another embodiment, the coupling mechanism provides a connection of the resonators using a waveguide. By varying the connection of the resonators with respect to the waveguide, positive relative coupling and/or negative relative coupling of the electromagnetic energy transferred between the waveguide and the resonators is provided.

Abstract: A plurality of end caps engagable with a microwave cavity each have an underside configured differently to cause the microwave cavity to have different electrical responses depending on which end cap engages the microwave cavity. A microwave device includes a cylindrical cavity and an end cap movable within the cavity to change its axial position within the cavity thereby varying the volume and the electrical response of the cavity.

Abstract: An electromagnetic wave component uses one or more diaphragms secured to the interior of a waveguide structure to tune its resonant frequency, with each diaphragm engaged by one or more adjustment members that deform it. The adjustment members are preferably screws that are threaded through the structure to push and/or pull on the diaphragms, thereby tuning the electromagnetic wave component. The shift in the resonant frequency of the electromagnetic wave component due to temperature-induced dimensional changes is mitigated if the materials used for the diaphragm, the adjustment members and the structure which houses the diaphragm are chosen to have an appropriate combination of thermal coefficients of expansion.

Abstract: A microwave filter has first and second subfilters. Each subfilter has at least one single mode resonator and a preset electrical response. The second subfilter is cascaded to the first subfilter by coupling one of the at least one single mode resonator of the first subfilter to one of the at least one single mode resonator of the second subfilter. The microwave filter has an overall transfer function dependent upon the selection of the first and second subfilters from a plurality of subfilters having different preset electrical responses.

Abstract: An ortho mode transducer (OMT)/multiplexer assembly having a corrugated junction and a coaxial dual mode waveguide resonator disposed around a central cylindrical waveguide. The corrugated junction diplexes signals, the higher frequencies passing through the central cylindrical waveguide and the lower frequencies passing through the coaxial dual mode resonator. Apertures in the dual mode resonator couple to an exit port and extract a first polarization from the lower frequencies passing through the dual mode resonator. The assembly may include a second aperture in the dual mode resonator for extracting a second polarization in a manner similar to the operation of the first aperture.

Abstract: An electromagnetic wave component uses one or more diaphragms secured to the interior of a waveguide structure to tune its resonant frequency, with each diaphragm engaged by one or more adjustment members that deform it. The adjustment members are preferably screws that are threaded through the structure to push and/or pull on the diaphragms, thereby tuning the electromagnetic wave component. The shift in the resonant frequency of the electromagnetic wave component due to temperature-induced dimensional changes is mitigated if the materials used for the diaphragm, the adjustment members and the structure which houses the diaphragm are chosen to have an appropriate combination of thermal coefficients of expansion.

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 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 is located in a common wall separating two microwave enclosures such as waveguides and cavities for coupling electromagnetic power between the two enclosures. The iris is formed of an aperture elongated in one direction to define a longitudinal axis of the aperture with opposed first and second sides parallel to the axis. Portions of the common wall at peripheral regions of the aperture are extended from the first and second sides towards the iris and perpendicularly thereto to form teeth, there being an array of teeth extending from the first side and an array of teeth extending from the second side. The teeth are readily polarized as magnetic dipoles by surface currents induced in the wall by electromagnetic waves for increased coefficient of coupling of electromagnetic field components through the iris.

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.