Abstract: A canister antenna including a radar transparent housing disposed about an axis and enclosing an antenna assembly having a plurality of integrated radiating elements. The radiating elements are configured to: (ii) produce a pseudo-omnidirectional radiation pattern of RF energy about the axis and (ii) selectively orient at least one null along a radial of the axis.

Abstract: A canister antenna including a radar transparent housing enclosing an antenna assembly having a plurality of integrated sector antennas. The sector antennas are configured to produce a pseudo-omnidirectional radiation pattern of RF energy about the axis.

Abstract: A canister antenna including a radar transparent housing disposed about an axis and enclosing an antenna assembly having a plurality of integrated radiating elements. The radiating elements are configured to: (ii) produce a pseudo-omnidirectional radiation pattern of RF energy about the axis and (ii) selectively orient at least one null along a radial of the axis.

Abstract: A canister antenna including a radar transparent housing enclosing an antenna assembly having a plurality of integrated sector antennas. The sector antennas are configured to produce a pseudo-omnidirectional radiation pattern of RF energy about the axis.

Abstract: A multi-cavity dielectric filter 30 having a single housing 32 for a plurality of resonant cavities 65. The dielectric filter 30 has a plurality of dielectric resonators 42 placed inside housing 32, instead of in individual housings, wherein the resonators 42 are spaced a quarter wave apart and are electrically isolated from one another by conductive isolation plates 44 positioned therebetween. The isolation plates 44 do not make continuous mechanical contact with the interior conducting surface of housing 32, but rather are spaced from the inner surface 77 of housing 32, thereby making assembly of the filter much simpler than if a solid RF connection had to be made. The resonators 42 are positioned inside the housing 32 between the isolation plates 44 and are supported by low loss, low dielectric constant spacers 46. End walls 59 complete the cavity formation at the termination ends 79 of housing 32.

Abstract: A technique for directly coupling multiple high frequency resonant cavity filters includes a common port 62 that is directly coupled to a coupling rod 76 that is mounted within a first high frequency resonant cavity filter housing 64 of a housing assembly 60. The coupling rod 76 is directly coupled by a conductor 74 to an coupling rod 72 that is mounted within a second high frequency resonant cavity filter housing 66. The conductor 74 passes through an opening 78 in a common wall 80 between the first 64 and the second 66 high frequency resonant cavity filter housings. Thus, both filters 64, 66 are directly coupled to the common port 62.

Abstract: A folded high frequency resonant cavity filter 30 includes a filter housing 32 that contains a half-wave resonator rod 36, 64 and a plurality of evanescent mode resonator rods 34, 34'. The half-wave resonator rod 36, 64 and plurality of evanescent mode resonator rods 34, 34' are mounted to the filter housing 32 such that they all lie along a single plane. The filter housing 32 has an inner wall 42 that physically isolates two groups of evanescent mode resonator rods 34, 34' from each other. An aperture 40 is is formed in the inner housing wall 42 between two physically opposing evanescent mode resonator rods 34' to allow a capacitive cross-coupling to occur between the two evanescent mode resonator rods 34'. The capacitive cross-coupling is fine tuned by a tuning rod 44 that is positioned through the inner wall 42 and within the aperture 40.

Abstract: A duplexing filter filters high frequency electromagnetic signals operating in two different frequency bands and uses a common coupling line mounted within an overall housing. Both filters use resonators and may be configured as combine or interdigital type filters. The high frequency filter has at least some of its resonators mounted on a base plate which in turn is positioned at a location along the length of the common coupling line so as to couple the higher frequency filter at its approximate quarter-wave location.

Abstract: Modular resonant cavities particularly for use in applications associated with high frequency electromagnetic energy each comprise a shell defining an aperture formed therethrough, and either end plates and/or divider closure plates, each having stepped-down regions for interfitting at perimeter ends of adjacent shells so as to form a resonant cavity. The modular resonant cavities include support rods passing through the corner regions of each closure plate. Fastening means at each end of the rods mechanically secure the modular resonant cavities together.

Abstract: A bandpass/lowpass filter comprises a bandpass filter with two or more resonators with the first and last resonators coupled to associated connectors. Corresponding lowpass filters are positioned within the first and last resonators, wherein each lowpass filter comprises a plurality of low impedance and high impedance elements. A disk emanates from each of these integrated lowpass filters so as to couple the filtered electromagnetic energy to the bandpass filter. The overall result is an integrated filter having a desired bandpass with significant suppression of spurious frequencies. The overall integrated filter is significantly smaller than conventional filters using external inline lowpass filters.

Abstract: A dielectric notch resonator particularly suitable for use in a band reject filter operable at ultra-high frequencies comprises a dielectric resonator and an associated housing which results in a reactance having an imaginary component effectively nulled by a coupling reactance mechanism forming part of the dielectric notch resonator so as to present a relatively low resistive impedance load at a given center frequency and frequencies in a narrow bandwidth thereabout. The coupling reactive mechanism comprises an inductive wire and a serially connected variable capacitor so as to null the reactive component of the dielectric resonator at a particular center frequency and to modify the symmetry of the rejected frequency bandwidth by adjusting the capacitance of the variable capacitor.

Abstract: A dielectric notch filter for attenuating frequencies of relatively narrow bandwidth in comparison to the center frequency of operation, and particularly for attenuating such narrow bandwidths in the ultra-high frequency electromagnetic spectrum. The dielectric notch filter comprises a plurality of dielectric notch resonators coupled to a transmission line at slightly less than the quarter wavelength of the center frequency of the attenuation frequency bandwidth so as to minimize interaction between the individual dielectric notch resonators. Each dielectric notch resonator comprises a dielectric resonator, an associated housing and a coupling reactance element which in turn comprises an inductive wire and a variable capacitor so as to null the reactive component of the dielectric resonator, thereby resulting in a highly attenuated resonant frequency having little imaginary component about said center frequency.