Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: A dielectric travelling wave antenna (DTWA) using a TEM mode transmission line and variable dielectric substrate.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: A dielectric travelling wave antenna (DTWA) using a TEM mode transmission line and variable dielectric substrate.

Abstract: A Nuclear Quadrupole Resonance detection system with features that include: a) slab radiating structure for the transmit path; b) reduced impedance transmit radiator; c) portal-embedded stripline couplers for receive path; d) wideband chirps each encompassing multiple simultaneous resonances; e) chirp sequencing enabling three channel architecture; f) magnetic amplification effect of ferrite-based directional couplers; g) determining position of substance within portal.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: A cylindrically symmetric satellite antenna that provides directional and omnidirectional operating modes in a compact form factor. Feed points located at the top of the cylindrical structure provide increased platform isolation. Combining networks, disposed below or within the cylindrical structure, may be replaced with inexpensive baluns composed of coaxial line sections.

Abstract: Techniques for implementing series-fed antenna arrays with a variable dielectric waveguide. In one implementation, coupling elements with optional controlled phase shifters are placed adjacent each radiating element of the array. To avoid frequency sensitivity of the resulting array, one or more waveguides have a variable propagation constant. The variable waveguide may use certain materials exhibiting this phenomenon, or may have configurable gaps between layers. Plated-through holes and pins can control the gaps; and/or a 2-D circular or a rectangular travelling wave array of scattering elements can be used as well.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: A Nuclear Quadrupole Resonance detection system with features that include: a) slab radiating structure for the transmit path; b) reduced impedance transmit radiator; c) portal-embedded stripline couplers for receive path; d) wideband chirps each encompassing multiple simultaneous resonances; e) chirp sequencing enabling three channel architecture; f) magnetic amplification effect of ferrite-based directional couplers; g) determining position of substance within portal.

Abstract: A cylindrically symmetric satellite antenna that provides directional and omnidirectional operating modes in a compact form factor. Feed points located at the top of the cylindrical structure provide increased platform isolation. Combining networks, disposed below or within the cylindrical structure, may be replaced with inexpensive baluns composed of coaxial line sections.

Abstract: An compact manpack format antenna operating over a broad bandwidth. In one arrangement, the antenna is formed from a set of five hollow cylindrical conductive elements. Several cylinders provide, for example, a VHF/UHF radiator section and other cylinders form an L-band radiator section. A bottom leg of the L-band section operates as part of the VHF/UHF section via coupling between that lower L-band leg and the VHF/UHF section. This coupling arrangement reduces the required overall physical length of the antenna.

Abstract: Disclosed is a multiband jamming antenna for use with RF jamming systems. An exemplary embodiment of the antenna comprises high-band, medium-band and low-band radiating structures arranged in a collinear manner. The three radiating structures are operable in three respective overlapping frequency bands. In the exemplary embodiment, the high-band radiating structure comprises a hybrid biconical/dipole antenna disposed at an upper end of the antenna. The medium-band radiating structure is collinearly coupled to the high-band radiating structure and comprises upper and lower dipole elements that are tuned using a dual section coaxial transformer. The low-band radiating structure is collinearly coupled to the medium-band radiating structure. The low-band radiating structure comprises a coaxial Ruthroff UNUN transformer that is coupled to the low-band radiating structure, and a feeder cable that connected to the coaxial Ruthroff UNUN transformer, and the high-band, medium-band, and low-band radiating structures.

Abstract: Disclosed is a multiband jamming antenna for use with RF jamming systems. An exemplary embodiment of the antenna comprises high-band, medium-band and low-band radiating structures arranged in a collinear manner. The three radiating structures are operable in three respective overlapping frequency bands. In the exemplary embodiment, the high-band radiating structure comprises a hybrid biconical/dipole antenna disposed at an upper end of the antenna. The medium-band radiating structure is collinearly coupled to the high-band radiating structure and comprises upper and lower dipole elements that are tuned using a dual section coaxial transformer. The low-band radiating structure is collinearly coupled to the medium-band radiating structure. The low-band radiating structure comprises a coaxial Ruthroff UNUN transformer that is coupled to the low-band radiating structure, and a feeder cable that connected to the coaxial Ruthroff UNUN transformer, and the high-band, medium-band, and low-band radiating structures.