Abstract: Disclosed is a circular waveguide in which a slots are formed which are shaped and disposed such that they interrupt either the right hand or left hand circulating mode (RC and LC respectively) residing in the waveguide. Locating the slots in the waveguide wall is accomplished in accordance with the theory that for TE modes in circular waveguide with circumferential variation of e.sup..+-.jm.phi., current flow lines are produced that are helical. The slots are located so as to interrupt the helical current of the desired mode. In one embodiment, an ortho-polarization mode transducer and a circular polarizer are used to feed the slotted waveguide. By control of the amplitude and phase of the energy propagating in the waveguide, azimuthal pattern control can be effected. By dielectric loading the waveguide to make .lambda.g in the loaded waveguide equal to .lambda.-free space, endfire radiation can be achieved.

Abstract: An optical limited scan antenna system is disclosed. The invention is a dual lens type array antenna system with a small array feed network. The system includes a bootlace-type microwave aperture lens with an array of radiating elements arranged along the linear aperture and an array of pickup elements arranged along the curved inner surface, an intermediate optical corrective lens, a feed array for illuminating the corrective lens with a source distribution, and with a power divider and phase shifters arranged to drive the feed array. The corrective lens is circularly symmetric (spherically symmetric in the three-dimensional case), and its radially varying dielectric constant is such that a point source on its surface is focused to an image point on the inner surface. The pickup elements on the curved surface of the aperture lens are coupled to corresponding radiating elements on the linear aperture.

Abstract: A variable inductor usable in a fast tuning RF network comprises a plurality of inductor switching circuits connected in series. Each inductor switching circuit includes an input terminal connected to a discrete inductor and to a PIN diode, and includes an output terminal connected to switches which are in turn connected to the parallel connected discrete inductor and PIN diode. The PIN diode operates in either the forward bias mode for switching out the respective discrete inductor, or in the reverse bias mode for switching in the respective discrete inductor. The PIN diode is forward or reverse biased by MOSFET switches one of which has a parasitic capacitor used to provide a charged rectified reverse bias voltage to the PIN diode to insure reverse bias operation during large voltage changes in the conducted RF signals. The MOSFET switches are controlled by logic signals so that rapid switching by computer or other processor control is possible.

Abstract: A touch panel system for displays is provided having electromagnetic energy interference shielding arrangements coupled with other features for an integrated, easily maintained, operator-adapted touch panel system. The system includes an electromagnetic energy interference shielding bezel mounted at the front of the display unit to an outer display housing. The bezel is integrated with an optically transparent and electrically conductive faceplate covering the display, and a raised border with an associated electromagnetic energy interference seal located at the periphery of the active touch panel area which is disposed between the faceplate and the bezel to complete an electrical path. The faceplate is roughened to disperse spatial interference patterns and reflections, and in one embodiment, has an electrically conductive wire mesh disposed within it for electromagnetic energy interference sealing and contrast enhancement for filtering extraneous light in the manner of a venetian blind.

Abstract: An image registration system for registering multiple images on a screen is disclosed. A registration pattern is projected on the screen along with the image to be registered and in a fixed position in that image. A sensor apparatus for each image, having three photodetectors disposed in a right angle relationship is mounted on the screen at a predetermined location for determining the position of the registration pattern on the screen. The position of the registration pattern on the screen is determined by comparing the outputs of the three photodetectors. Difference signals are produced by the comparisons and are used to reposition the projected image to bring it into registration. The sensor apparatus are disposed so that when the registration patterns are in register with them, the images are in register with each other.

Abstract: A single two dimension radar system having the capability of developing two dimensional data on all targets in its surveillance volume and three dimensional data for selected targets in its surveillance volume is disclosed. A single phased array antenna having two selectable elevation beam patterns, a wide beam and a narrow beam, is rotated in azimuth. In the two dimension mode, targets are detected and tracked in an azimuth and range position through use of the wide elevation beam. Upon selecting a particular target in track for three dimension data extraction, the radar system changes to the three dimension mode prior to the azimuth position of the selected target, and performs a sequential lobing process of the narrow beam in elevation angle. The power ratios of the target returns in the sequential lobes are analyzed and an elevation position of the selected target is determined. The radar system reverts to the two dimension mode after leaving the azimuth position of the selected target.

Abstract: A cylindrical cavity-backed multipole antenna system for high frequency applications is disclosed. The antenna system comprises a plurality N of planar radiation elements disposed on a dielectric disc mounted on the top surface of a conductive cylindrical cavity and equally spaced about its axis. A network circuit is adapted to introduce, for the system sum signal, progressive phase shifts of 360.degree./N to signals associated with adjacent elements and, for the difference signal, progressive phase shifts of 720.degree./N. The antenna system may be used to both transmit and receive electromagnetic radiation. The antenna sum and difference patterns are substantially symmetric in space about the antenna boresight.

Abstract: An articulated linkage is disclosed for supporting waveguide and electrical cabling through a predetermined range of movement. The linkage comprises a plurality of elongated rigid sections, joined by articulated joint sections. The joints comprise at least two short links which are pivotably connected to each other and the adjacent rigid sections. Travel limit pins are provided to limit the pivoting motion of the joint links relative to each other and the rigid sections. The lines of waveguide comprise respective sections of flexible waveguide passing through the flexible joints of the linkage and are connected to elongated sections of rigid waveguide which are supported by the rigid sections of the linkage. The travel limits on joint movement are selected to limit the angular excursions to protect the flexible waveguide from undue stresses during movement of the linkage.

Abstract: A pseudorandom noise generator which operates in different modes is disclosed. The pseudorandom noise generator (10) includes circuitry (11,13) for providing a digital signal having a pseudorandom sequence at a selected clock rate; a modulation control circuit (15, 17, 20, 23) for selectively providing a modulation control signal that corresponds to either a non-filtered or filtered version of the digital signal, and for controlling the mode of operation of the noise generator; a modulation circuit (27, 29, 31, 33) responsive to the modulation control signal for providing a modulation signal; and a voltage controlled oscillator (VCO) (35) responsive to the modulation signal for providing a VCO output having a relatively constant output spectrum and high spectral containment for each mode of operation pursuant to control by the modulation control circuit and the modulation circuit.

Abstract: Ribbon termination member has thread therein for connection to a coupling between sections of the towed array. First and second pins have cylindrically curved front surfaces upon which legs of the flexible ribbon tension member are engaged. The curved surfaces permit transfer of tension loads between the flexible tension ribbon and the pins. The second pin has an extended bearing surface 92 for preventing damage to the ribbon when loads are out-of-line.

Abstract: An electronically scanned array antenna useful for millimeter wavelength energy is disclosed. The antenna comprises a fully ferrite loaded square or round waveguide having radiating apertures spaced along part of its length. Rf energy is circularly polarized in the waveguide. The phase velocity of the wave is controlled by applying a longitudinal magnetic field to the ferrite to produce a controllable linear progressive phase of the energy radiated from the apertures to form a beam in the desired direction. The phase control is of a latching type using flux drive. The particular structure of the invention enables combining a plurality of branching array elements with a feed element to form an array capable of two dimension beam scanning.