Abstract: Disclosed is a multiarm spiral antenna for wideband transmission and reception of both right-hand and left-hand circularly polarized electromagnetic energy. Each antenna arm includes a series of cells wherein the impedance of the antenna arm monotonically decreases over a first portion of the cell length and monotonically increases over a second portion of the cell length to thereby provide the signal reflection necessary for mode conversion (operation in both polarization senses) without introducing abrupt impedance transitions. Various cell geometry that can be employed is described.

Abstract: A feed system for a microstrip or stripline antenna includes a serpentine traveling feed located in the plane of interleaved arrays along which a first signal propagates. A chain of crossover structures serves as a second traveling feed, extends in coplanar parallel spaced relation to the first feed, and carries a second propagated signal therealong. First and second ports of each structure connect the serpentine feed to a first group of arrays for coupling the first signal therebetween while third and fourth ports of each structure couple the second signal to a second set of arrays without significant interaction therebetween.

Abstract: To provide broad bandwidth in a multiple-band directional antenna, the antenna includes an array of parallel horizontal elements, which are: (1) an open-sleeve dipole as the driven element; (2) a trap director element; and (3) trap reflector elements. The driven element includes: (1) a trap central dipole which is center-fed and has sections self-resonant within the bands of 21.0 to 21.45 megahertz and 14.0 to 14.35 megahertz; and (2) two unequal-length sleeves self-resonant at 28.0 to 29.7 megahertz. The director and reflector elements are resonant in the same bands and are spaced and tuned for directivity of the array.

Abstract: A horn-reflector antenna comprising a paraboloidal reflector for transmitting and receiving microwave energy, and a flared feed horn for guiding microwave energy to and from the reflector, the longitudinal shape of at least a section of the horn at the end where the horn begins to flare outwardly being defined by the equation ##EQU1## where R is the transverse dimension from the longitudinal axis of the horn to the side wall of the horn 1 is the axial distance along the horn measured from the end where the horn begins to flare outwardly, R.sub.1 and R.sub.2 are the radii of the horn at opposite ends of the horn section defined by the equation, L is the axial length of the horn section defined by the equation, and the exponent p has a value greater than two and less than about 7, to effect a substantial reduction in the TM.sub.11 mode level.

Abstract: An array of axially oriented thin resistive elements having a certain value of conductance or resistance in the axial direction is supported in dielectric material. For a wave at normal incidence, the apparatus is essentially invisible. For a wave incident at oblique angles in the E plane, current is induced in the resistive elements and dissipative attenuation occurs. The attenuation does not rely on resonance so that the apparatus operates over a wide frequency band and does not require tight dimensional tolerances.

Abstract: This invention relates to a multi-beam antenna and a method of configuring the same, where the antenna consists of a main reflector, a plurality of horns for exciting the main reflector, and separate sub-reflectors for correcting phase errors of respective beams caused by reflection at the main reflector, or an integrated sub-reflector which is substituted for said separated sub-reflectors.

Abstract: Two separate microstrip antennas are interleaved in the same plane thereby occupying substantially the same area as a single antenna. Each antenna aperture produces two beams and the configuration for each antenna includes a single feed on each planar array which results in lowered overwater bias error. Each planar array antenna can have radiating arrays of different radiator spacing. Using forward firing arrays for one antenna and backward firing arrays for the other antenna, a radiated spacing is chosen for each interleaved antenna which results in temperature compensation in the along track direction.

Abstract: A telescoping boat light-antenna for use on a vessel which is recessed below the level of the deck when not being utilized and is capable of being extended to a predetermined height above the deck through a telescoping motor assembly when being utilized as either a boat light or an antenna. The light-antenna includes a recessed cup below a base plate which supports the light lens below deck level when recessed therein in a non-utilized position and provides for extension of the telescoping tubing when the light-antenna is in a telescoped position. The twofold purpose of the light and antenna provides for military function in communications command and control of the vessel as well as safety at sea.

Abstract: An apparatus for illuminating and forming an image of a specimen has a transparent specimen-supporting surface and a fiber-optic bundle divided into illumination fibers which illuminate the surface and emission fibers which are held in the same relative spatial orientation throughout their length so that they produce an image of a specimen on the surface. This image may be analyzed by an optical demultiplexer using a light gate in which groups of input pixels are associated with a single output pixel, the light gate being switchable between various light-transmission states in each of which only one of the input pixels in each groups is allowed to transmit to the output pixel, so that the light gate effectively divides a single image comprising a large number of pixels into a series of images each containing fewer pixels. This enables a single photodetector chip to produce electronic signals representing an image having a much larger number of pixels than the number of separate photodetectors on the chip.

Abstract: An active windshield antenna has a first conductor extending parallel to a metal frame to the vertical line of symmetry of the latter, a second conductor extending in a bending point from said first conductor along the symmetry line, an amplifier has separate transmission paths for a low frequent low medium short wave region and ultra short wave region, the transmission path of the long medium short wave region at an inlet of the low medium short wave amplifier has a high input impedance, and the input impedance of the total amplifier in the low medium short frequency region is high.

Abstract: An omni-directional antenna having two circular conductors of about 163/4 inches in diameter, concentrically disposed in planes about 4 inches apart is disclosed. The adjacent ends of the two circles of wire are each connected together. The connected ends are insulated from each other and are connected to a lead in transmission line of 300 ohms impedance.

Abstract: A polarizer reflector includes a reflecting layer backing a meander-line polarizer effective to convert the incident beam from linear polarization to circular polarization during the propagation of the beam forwardly through the polarizer, and to reconvert the beam reflected from the reflecting layer from circular polarization to linear polarization but rotated at a predetermined angle, preferably at a right angle, with respect to the polarization of the incident beam. Also described is a reflecting plate-type scanning antenna including a front collimating paraboloid reflector with the above-described polarizer reflector serving as the back reflector, which arrangement has been found to substantially increase the frequency range of the scanning antenna.

Abstract: A portable radio is provided with a whip antenna that can be removed and replaced without requiring the disassembly of the radio. The antenna is removed and replaced through an opening in the radio housing, and it is secured in its assembled position by a fastener extending through another opening in the housing.

Abstract: Mounting apparatus is illustrated for a TV satellite dish antenna wherein nonbinding adjustment means are provided for accommodating the dish antenna for use in particular geographical location, and wherein means are provided for mounting dish antennas upon a tiltable frame wherein bracket supports are adjustable so that a leg may be accommodated in tangential relation to any selected dish size and configuration.

Abstract: A vertically oriented dipole antenna system for filling in overhead radiation or reception coverage with equidirectional-linear polarization (a linearly polarized field vector which lies in the plane of the system's vertical and horizontal axes) having, in combination, a balanced vertically oriented cylindrical dipole the inner adjacent ends of the elements of which are connected to supplemental conductors at points near the inner end of one element substantially ninety degrees apart along the circumference of the element and each extending outward a distance of the order of 0.15 of the wavelength of the mean frequency with which the antenna is to be operated and at an acute angle of the order of 33.degree.

Abstract: A stabilized antenna system is disclosed. The stabilized antenna platform includes an acceleration displaceable mass which compensates for linear acceleration forces to inhibit tipping of the antenna platform. The stabilized antenna system may include in combination a gimbal mounting and one or more gyros.

Abstract: A bi-directional antenna array is disclosed having at least two vertical loop antennas arranged mutually perpendicular individually operable to produce bi-directional scanning patterns shifted ninety degrees to achieve significant side rejection so that a user can better utilize the congested frequency spectrum.

Abstract: A planar log periodic quad array comprising a two-conductor twisted transmission line to which log periodic elements are connected. The elements are arranged in two sets on opposite sides of the transmission line and are in a common plane. Each element has two points of connection with a particular conductor of the transmission line and comprises two sides each extending from a respective one of the two points of connection to the particular conductor to join at a corner which lies on an imaginary line perpendicular to the transmission line at its center feed point. Immediately adjacent elements of one set are connected to alternate ones of the two conductors of the transmission line and each element of the other set has a general geometric symmetry about the transmission line with respect to a corresponding element of the one set but with its points of connection to the transmission line being to the opposite conductor. The array is suited for active or passive use and has a broadband characteristic.

Abstract: A frequency conversion interface is disposed between the main and subreflectors in a multiple beam antenna system so that the antenna system amplification factor will be defined by m=(f.sub.1 /f.sub.2).multidot.(.omega..sub.1 /.omega..sub.2), to permit large main reflector to subreflector area ratios while maintaining small amplification factors.

Abstract: A circular frequency-independent antenna array (10) includes a plurality of radially extending log-periodic subarrays (12, 14, 16, 18, 20, and 22) of slot radiators (26) provided in a ground-plane conductor (28). Associated with each slot is a cavity (34) into which the slot opens. A traveling-wave element in the form of a wire (30) cooperates with a ground-plane conductor (28) in which the slots are provided to support propagation of an electromagnetic signal. The signal is radiated upon encountering a slot that resonates at a frequency near that of the signal, and the depths of the cavities are adjusted so that the phase relationships between the radiation from the slots and the signal propagated along the traveling-wave element results in an antenna pattern that launches radiation in a direction away from the center of the array. Direction-finding errors are reduced because interference between the several subarrays is kept to a minimum.