Abstract: A Radio Frequency (RF) microstrip antenna employs a planar or curved radiator element that is mounted or supported in spaced relation to a planar or curved ground plane element A RF feed is attached near one edge of the radiator element for receiving and/or transmitting RF signals; in a lobe that is substantially perpendicular to the ground plane element. The radiator element and the ground plane element are maintained in a converging inclined or tilted physical relationship. When a coaxial cable is employed as the antenna feed, the cable's outer insulation is secured to the ground plane element, the cable's center conductor extends away from the ground plane element to provide a signal feed to the radiator element and to provide physical support for one edge of the radiator element, and two insulator posts extend away from the ground plane element to provide support for the opposite edge of the radiator element.

Abstract: A photonically controlled antenna array is made of a plurality of stacked light waveguides made of a material such as silicon whereon each of which one or more photonically controlled antenna elements are mounted. Light is injected into ones of the light waveguides and reflects therein until it is absorbed by the antenna elements mounted thereon due to the higher refractive index of silicon. When the photonically controlled antenna elements are illuminated they are switched to a conductive state and can transmit and receive electromagnetic signals. When no light is injected into the light waveguide the photonically controlled antenna elements are not illuminated and are in a non-conductive state wherein they cannot receive or transmit electromagnetic signals.

Abstract: Wastewaters which are contaminated with heterocyclic aromatic compounds, especially wastewaters contaminated with biocidal heterocyclic aromatic compounds, or the by-products and intermediates thereof, can be treated to largely or even substantially completely degrade the heterocyclic aromatic rings by a process which comprises either adjusting the pH of said wastewaters to at least 11 and heating in a sealed vessel at a temperature of 120.degree. C. to 175.degree. C., or adjusting the pH of said wastewaters to 2.5 or less and heating in a sealed vessel at a temperature of 130.degree. C. to 175.degree. C., for an effective length of time.

Abstract: An inexpensive, efficient, broadband, slot-type antenna with unidirectional sensitivity includes a slot-forming means defining a plurality of substantially concentric and generally coplanar annular slots and a non-resonant antenna connection means for transmitting electromagnetic energy to and from the plurality of annular slots. The antenna connection means forms a plurality of non-resonant, radially-extending cavities that are adapted to combine electromagnetic energy received at the plurality of concentric, annular slots substantially in phase and to divide electromagnetic energy between the plurality of concentric, annular slots for transmission from the slots generally in phase and along the central slot axis that lies perpendicular to the two concentric, annular, coplanar slots.

Abstract: The subject invention relates to antennas having substantially greater bandwidth and low angle gain of the type for the transceiving of circularly/elliptically polarized electromagnetic waves. The antenna structure comprises a ground plane, a source of linearly-polarized wave energy field associated with said ground plane, and a plurality of conductive elements having an L-shape, said elements equally spaced from one another and equiangularly disposed about the sources, said plurality of elements being in a form of a circular arrangements, each element being so disposed as to fall on the circumference of the circular arrangement, each element lying in a common plane orthogonal to the linearly-polarized wave energy field provided by said source. The subject invention has special utility in motor and marine craft for communication and navigation.

Abstract: A compact, easy to manufacture quarter-wavelength microstrip element especially suited for use as a mobile radio antenna has performance which is equal to or better than conventional quarter wavelength whip-type mobile radio antennas. The antenna is not visible to a passerby observer when installed, since it is literally part of the vehicle. The microstrip radiating element is conformal to a passenger vehicle, and may, for example, be mounted under a plastic roof between the roof and the headliner.

Abstract: A compact, easy to manufacture quarter-wavelength microstrip element especially suited for use as a mobile radio antenna has performance which is equal to or better than conventional quarter wavelength whip-type mobile radio antennas. The antenna is not visible to a passerby observer when installed, since it is literally part of the vehicle. The microstrip radiating element is conformal to a passenger vehicle, and may, for example, be mounted under a plastic roof between the roof and the headliner.

Abstract: A controllable dual input/output port power divider coupled with a controllable phase shifter feed a dual ported dual polarized microstrip antenna structure. By controlling the power divider and phase shifter, arbitrary orthogonal polarization (e.g., linear, circular or elliptical) radiated r.f. fields are obtained. Virtually the entire structure comprising the dual port power divider, phase shifter and microstrip radiator may be formed of shaped photo-chemically etched microstrip conductors disposed a very short distance (e.g., less than one-tenth wavelength) above a conductive reference surface.

Abstract: A relatively broadband printed circuit antenna structure includes a dielectric sheet having printed circuit-like conductive structures printed on both sides in predetermined registration with one another. A traditional non-radiating microstrip transmission line structure extends from a common r.f. feedpoint to at least one terminal end portion. However, apertures disposed within the underlying (or overlying) conductive reference surface of the double-cladded printed circuit board in the vicinity of each terminal end cause substantial r.f. radiation to occur over a relatively broader bandwidth than with a more traditional microstrip antenna radiator structure. In one embodiment, the aperture in the microstrip ground plane itself becomes a radiating aperture due to the transmission line currents flowing within the ground plane.

Abstract: Method and apparatus is disclosed for detecting a security threat in a zone. A transmitter within the zone directs a first microwave signal of frequency f.sub.0 to a reflector. The reflector doubles the frequency to 2f.sub.0 and reradiates it to a receiver. The receiver correlates the reflected signal (phase and/or amplitude) with the transmitted signal and provides spectral data to a digital signal processor. A seismic sensor within the security zone also provides seismic spectral data to the digital signal processor whenever seismic disturbances are detected within the zone. The digital signal processor compares the spectral data with predetermined stored spectral data. Whenever both the reflector signal and the seismic signal spectra indicate a security threat within the zone, an alarm signal is output. Loss of reflector output plus adverse seismic spectral data may also trigger an alarm. The dual-sensor configuration reduces false alarms and circumvention of the detection system.

Abstract: A passive array of resonantly-dimensioned microstrip antenna radiator patches are closely spaced (i.e., less than one-tenth wavelength) above a ground plane and individually associated with transmission line segments terminated so as to cause the overall array to receive an incident r.f. electromagnetic field, to convert the received field into r.f. electrical currents which flow along the transmission lines and are absorbed by the terminations or reflected therefrom. In the latter case, the reflected r.f. energy is re-transmitted in a predetermined direction as a re-directed r.f. electromagnetic field. The presently preferred embodiment is a relatively thin, flexible and thus conformable layered structure formed by selectively etching conductive material from one side of a metallically cladded dielectric sheet. For satellite communication, a flat reflectarray may be associated with a primary r.f.

Abstract: First and second annular r.f. radiating structures are mounted for concentric relative rotational motion with their r.f. radiation patterns directed toward one another. The annular r.f. radiating structures may be realized, for example, by cylindrically conformed microstrip antenna radiators which define tuned resonant cavities feeding one or more radiation apertures defined between an edge of a microstrip radiator "patch" and an underlying electrical reference or ground surface. The microstrip radiator "patch" may be either continuous in its circumferential dimensions or it may have occasional circumferential discontinuities formed by axially directed gaps therein. If the total circumferential dimension is greater than one wavelength at the intended operating frequency, then a corporate structured feedline provides plural spaced-apart feedpoints about the circumference so as to achieve a substantially uniform distribution of r.f. field amplitudes and phases about the circumference.

Abstract: The wide ends of two similar horn structures are juxtaposed and joined by a rotary bearing extending thereabout which permits relative rotational motion between the two horn structures. A field shaping lens may be disposed at the relatively rotatable horn juncture to help insure substantially planar wavefront shapes across the relatively rotatable joint. An annular aperture may also be provided between the relatively rotatable horns and electrically loaded so as to present an approximate short circuit electrical impedance at the intended frequency of operation.

Abstract: A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single semi-insulating GaAs substrate by means of a controlled fabrication process sequence.The resulting integrated circuit structure built upon a semi-insulating GaAs substrate provides a unique monolithic structure capable not only of phase-shifting, amplifying or otherwise controlling and conducting r.f. electrical signals but also capable of directly radiating/receiving r.f. electromagnetic emanations propagated to/from the integral antenna elements of the monolithic structure.

Abstract: A pair of spaced apart resonant microstrip radiators is fed from two differently polarized input/output ports by respective different feedlines to achieve different respective polarizations while at the same time minimizing undesirable r.f. coupling between the input/output ports. The preferred design embodiment minimizes feedline length while simultaneously increasing the r.f. isolation between the two differently polarized input/output ports.

Abstract: A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single substrate by means of a controlled fabrication process sequence.

Abstract: A resonant metallic conductor having a nominal resonant frequency which varies inversely with temperature is temperature compensated by association with a predetermined proportion of dielectric material which acts to increase the nominal resonant frequency with temperature so as to substantially temperature compensate an antenna structure.

Abstract: Method and apparatus for improving the r.f. isolation between a transmitting and receiving antenna disposed at respectively corresponding spaced apart but relatively adjacent locations. A special compensation radiator is provided at the transmitting and/or receiving antenna site and fed from the same r.f. input/output which feeds the main antenna. The direction, magnitude and phase of r.f. energy radiated and/or received from the compensating radiator are chosen so as to substantially cancel the undesirable r.f. energy otherwise directly received by the receiving antenna from the transmitting antenna.

Abstract: A microstrip antenna structure formed from a unitary conducting surface separated from a ground plane by a dielectric film where the r.f. radiator and feedlines form a generally planar arrangement of unitary integrally formed electrical conductors. The r.f. radiators are fed from an outside edge to selectively produce linearly and/or circularly polarized radiation at a selected resonant frequency(s). Necessary fixed phase shifting circuits are integrally formed by printed circuit techniques in the generally planar arrangement of electrical conductors for the circularly polarized radiators. A plurality of such antenna elements are also formed into a phased antenna array to achieve substantially ideal array gain thus producing an extremely high gain antenna with inexpensive printed circuit board construction techniques.

Abstract: A monolithic microwave integrated circuit including an integral array antenna. The system includes radiating elements, feed network, phasing network, active and/or passive semiconductor devices, digital logic interface circuits and a microcomputer controller simultaneously incorporated on a single semi-insulating GaAs substrate by means of a controlled fabrication process sequence.The resulting integrated circuit structure built upon a semi-insulating GaAs substrate provides a unique monolithic structure capable not only of phase-shifting, amplifying or otherwise controlling and conducting r.f. electrical signals but also capable of directly radiating/receiving r.f. electromagnetic emanations propagated to/from the integral antenna elements of the monolithic structure.