Abstract: An antenna is disclosed for increasing the gain of, or shaping the pattern of, a radiated radio frequency signal. The antenna includes a waveguide for directing the radio frequency signal or for receiving directively the radio signal, a first conductive reflector disposed beneath the waveguide and extending beyond the aperture of the waveguide for reflecting certain of the waves emanating from or entering the aperture of the waveguide, and a second reflector, which may be the mounting surface, disposed beneath the first reflector and extending beyond the first reflector for reflecting other of the waves emanating from or entering the aperture of the waveguide.

Abstract: An aperture antenna is provided having a substantially smooth and continuous concave reflective surface disposed about a longitudinal axis. The reflective surface has a peripheral edge lying in a first plane substantially perpendicular to the longitudinal axis, a transition boundary lying in a second plane substantially parallel to the first plane, and a transition zone located between the transition boundary and the peripheral edge. The reflective surface has surface resistivity in a selected portion of the transition zone substantially adjacent to the peripheral edge that is nonuniform as a function of positon on the reflective surface.

Abstract: A rotating reflector is used to provide a beam scan throughout a predetermined angle such as 360.degree.. A circular polarizer is coupled with the reflector and converts received linearly polarized energy into circularly polarized energy. A fixed feed is configured to receive the reflected circularly polarized energy and converts such energy to linearly polarized energy. The antenna system can receive the same linear polarization of energy throughout its 360.degree. scan angle without polarization mismatch or orthogonal polarization losses. The relative orientation of the two polarizers may be adjusted to receive any orientation of linear polarization of energy throughout the scan angle. For example, they may be oriented so that the antenna system receives vertically polarized energy, slant 45.degree. linearly polarized energy, or horizontally polarized energy.

Abstract: Circular open ended waveguide feeds for compact ranges. Feeds according to the present invention employ smaller apertures for a given frequency of operation than a standard compact range feed. According to a first embodiment of the invention, a circular open ended waveguide feed is constructed to operate with its lowest desired frequency of operation at approximately 1.01 times the cutoff frequency. A second embodiment includes a circular open-ended waveguide loaded with ridges to lower the cutoff frequency further and thus further reduce aperture size for a given bandwidth to radiate a broader beamwidth.

Abstract: Disclosed is a variable angle conical scanning antenna that employs an offset paraboloidal reflector which is rotated about an axis that extends through the focus of the paraboloid of revolution that defines the reflector. Electromagnetic energy is supplied to the reflector by an antenna feed that is mounted at the focus of the paraboloid of revolution and directed along the axis of rotation. In this arrangement the electromagnetic energy that is reflected from the offset paraboloidal reflector forms an angle between the axis of rotation and the beam of reflected electromagnetic energy that is equal to the angle between the axis of rotation and the focal axis of the paraboloid of revolution that defines the reflector. Thus, conical scanning at a cone angle that is equal to twice the angle between the axis of rotation and the reflected beam of electromagnetic energy is achieved as the offset paraboloidal reflector is rotated. Variable angle scanning (i.e.

Abstract: An antenna pointing device capable of scanning in two orthogonal directions comprises a fixed source (20) emitting a radio beam (21) and associated with a main offset reflector (10) and a secondary offset reflector (11), together with a set of at least three mirrors (14, 15, and 17) including a first mirror (14) aligned with the secondary reflector (11), and in which the second and third mirrors (15 and 17) are fixed to respective rotary drive mechanisms (16 and 18) for rotating them about two axes (.DELTA., .DELTA.') extending in orthogonal directions. The main and the secondary reflectors (10, 11) and the first and the second mirrors (14, 15) are mechanically fixed to one another in order to constitute a moving assembly. The second mechanism (18) drives both the third mirror (17) and said moving assembly (10, 11, 14, and 15).

Abstract: A low-cost, essentially self-contained microwave earth station having a reflector dish together with the microwave sensing/emitting elements embedded in a rigid, low density and low thermal conductivity plastic foam. At least the sides and back of the unit may be encased in a fiberglass-resin shell. Shielding for terrestrial interference also may be present. For a receive-only station, a low noise amplifier together with frequency conversion and channel selection (or all-channel transmission) to circuits may also be embedded in the foam. The only connections to such a receive-only unit are a line from a d-c source of power for supplying the required operating voltages to the electronics, and a coaxial cable supplying the selected one of the received information signals to the TV display or other device utilizing those signals. Preferably, a single coaxial line with the dual function of information output and d-c power input is employed.

Abstract: The present invention relates to an antenna comprising a plurality of feeds, and either a single reflector or a single lens wherein the reflector or lens includes a predetermined curved major surface that produces a maximum field of view in a first one of two principal planes of the antenna. The major curved surface is designed to produce a first and a second "stigmatic" focal point, which are spaced apart by a predetermined amount on either side of an axis normal to the center of the reflector or lens in the first principal plane, such that the coefficient of astigmatism is at a maximum predetermined tolerable amount at the center and at the opposite edges of the maximum field of view to produce a peanut-shaped area where the coefficient of astigmatism is within tolerable limits.

Abstract: An improved method for designing sector beam antennas. The method is used to provide a sector beam antenna having a feed horn with a cross sectional azimuth dimension and a cross sectional elevational dimension which are optimized to irradiate a reflector to transmit a signal over a coverage area such that the gain-area-product of the transmitted signal is maximized.

Abstract: Antenna horns for use as part of antenna system such as an offset parabolic antenna system. The horns of this antenna include a plurality of sections which enable the propagation of both the TE.sub.1,1 mode and the TM.sub.1,1 mode.

Abstract: The present invention relates to a high-power solid state amplifier arrangement comprising a large number of solid state amplifiers disposed in a waveguide array. The waveguide array is disposed in the aperture of an antenna feed arrangement at the image plane of an antenna feed to receive a uniform distribution over the array with substantially no spillover. Each of the large number of parallel waveguide sections of the array includes one or more solid state amplifiers in a serial, waveguide-interconnected, arrangement, and a wideband impedance matching arrangement in the waveguide configuration at the input and output of the section.

Abstract: A reflector antenna system with reduced blockage effects is provided by placing a compensating reflector between the surface of the main curved reflector and its primary feed to intercept illuminating radiation which would otherwise be blocked by the feed. The compensating reflector reflects the intercepted radiation with a beam pattern which is essentially identical to the substractive blockage pattern. The compensating reflector is spaced from the main reflecting surface to place its beam pattern in phase opposition to the blockage pattern to cancel common components from the blockage pattern.

Abstract: An antenna is provided equipped with a device which rotates the direction of the rectilinear polarization of a wave transmitted to a receiver (or transmitted by a transmitter) associated with the antenna, with respect to this same wave such as it is received by the antenna (or transmitted by the antenna). The device is formed from a square cross-section wavequide which is twisted in steps and which steps may be adjustable and which is twist guide inserted in the primary source of the antenna, between the horn of the antenna and the receiving (or transmitting) means associated with the antenna.

Abstract: A short-focus microwave reflector is located a short distance away from the feed horn and is positioned to reflect the beam of microwave radiation away from the feed axis and toward a large primary reflector antenna for transmission. A conical shield extends from the feed horn to the secondary reflector, joining them together as a unit and preventing sidelobe radiation. The beam of radiation emerges from the shield through an aperture in the sidewall thereof. The short focus of the secondary reflector causes the beam to be focussed approximately at the plane of the aperture, such that the beam diameter is small and the aperture can also be small, reducing stray radiation from the shield structure. Diffraction at the edges of the aperture is reduced by a radially surrounding choke structure which further suppresses sidelobe radiation.

Abstract: A feed horn for a reflector-type microwave antenna comprises a smooth-walled conical horn and a lining of absorber material on the inside wall of the horn for reducing the width of the RPE (radiation pattern envelope) in the E plane of the antenna. The lining of absorber material extends from the wide end of the conical feed toward the narrow end thereof, terminating at a point where the horn diameter is about 7 times the longest wavelength of the microwave signals being transmitted. The width of the RPE in the E-plane of the antenna can be reduced to be nearly equal to the width of the RPE of the H-plane of the antenna without significantly degrading this H-plane RPE from its shape without absorber and without significantly changing the gain of the antenna.

Abstract: A one-piece traffic radar unit has a housing containing both the transceiver and signal processing circuitry and the directional antenna of the radar system. A bracket plate extends from the top portion of the housing and overlies the dashboard of the patrol vehicle to mount the unit therein with the housing depending from the bracket plate in front of the dashboard, thereby leaving the driver's view through the windshield unobstructed. The antenna is of the conical horn type and is vertically disposed to beam the transmitted signal up through the housing to a rotary reflector mounted on the top of the housing. The reflector is rotatable about a vertical axis and permits the operator to aim the beam in any horizontal direction through the windshield or a window of the vehicle. A special safety mount for the reflector provides for 360.degree. rotation and also permits the reflector to break away from the housing on impact.

Abstract: A parabolic reflector antenna, designed to discriminate between incoming and outgoing waves having mutually orthogonal planes of polarization, has a ratio R between focal distance f and diameter D which, for optimum efficiency and cross-polarization decoupling, lies between 0.46 and 0.5 and operation in the TE.sub.11 mode and above 0.6 for operation in the dual TE.sub.11 +TM.sub.11 mode. An associated feed, in the shape of a slightly tapering horn of circular cross-section connected to a waveguide of square cross-section, has a relative aperture .alpha., defined as the ratio between its aperture radius r and the wavelength .lambda..sub.o at the center of the operating frequency band, which in the first instance ranges between 0.52 and 0.6 and in the second instance is given by kR+h with k.apprxeq.1 and h between about 0.1 and 0.15.

Abstract: A multifrequency, broadband, dual-polarized corrugated conical horn antenna is simultaneously fed a multiplicity of signals, two for each of five frequencies, with each of a pair of signals fed in each of two orthogonal planes for excitation of a desired spherical hybrid mode (HE.sub.11). The lowest frequency is fed into the horn through orthogonal pairs of colinear slots, each pair being fed by coaxial tee power dividers. Other signals are fed through a circular waveguide connected to the vertex. Band reject cavities block the next higher frequency from passing through the low frequency feed slots. The highest frequency signals are fed through orthogonal ports near the far end of the circular waveguide. The intermediate frequency signals are fed through orthogonal ports spaced along the waveguide.

Abstract: A cylindrical metal sheath surrounds the beam rays between the antenna and the passive reflector of a periscope arrangement; this sheath forms the support of the periscope arrangement as well as a screen against parasitic radiation.

Abstract: An antenna designed to emit a beam of generally elliptical cross-section has a reflector with a parabolic-elliptical concave surface conforming to the formula(x/p)+(y/q)=2zwhere p and q are the parameters of its parabolic cross-section in the xz and yz planes, respectively. A microwave feed located on a line interconnecting the foci of these two parabolas, preferably at the outer focus separated from the surface vertex by a distance q/2, generates a beam parallel to the axis whose ellipticity depends on the ratio q/p.

Abstract: Disclosed is an antenna feed system for use in satellite communication systems and the like, comprising a horn with a rectangular aperture and a waveguide connected thereto. The assembly formed by the waveguide and horn is constructed from two parts secured together so that the junction lies in the longitudinal symmetry plane parallel to the electric field of the TE.sub.01 mode and is mounted for rotation about the longitudinal axis of the waveguide. The feed system further comprises a polarization converter mounted in front of the horn for rotation about the extention of the longitudinal axis of the waveguide. The converter is constructed from a plurality of layers of supporting material each provided with a conductor which forms in one direction a mainly inductive load and in a direction which is perpendicular thereto a mainly capacitive load.

Abstract: A feed system for a dish-type microwave antenna has a primary radiator for directing a primary radiation pattern onto the dish-type antenna. A pair of symmetrical pattern control elements are aligned with the E plane of the antenna and extend radially outwardly from opposite sides of the axis of the primary radiator between the primary radiator and the antenna for increasing the antenna gain, reducing the sidelobe levels and reducing the half power beamwidth of the antenna in both the E and H planes. In an exemplary embodiment, the pattern control elements comprise metal strips mounted on the surface of a rigid coaxial cable extending along the axis of the primary radiator for transmitting microwaves to and from the primary radiator, and the metal strips are inclined toward the antenna.

Abstract: A universal antenna reflector providing a constant beam width pattern for any frequency of reflected electromagnetic energy illuminating the reflector is disclosed. The constant beam width reflected pattern is determined only by the characteristics of a particular antenna illuminating the reflector. The reflector is described by a family of curves the physical centers of each of which are coincident with and distributed along a unique backbone curve with each of the family of curves being perpendicular thereto.

Abstract: An improved antenna system of the type including a parabolic antenna with offset exciting in which only the upper portion of the parabola is used, an approximately horizontal bottom plate, and an exciter which is disposed above the bottom plate. The exciter has a tilt angle of about 50.degree.. The paraboloidal reflector is covered by a dielectric cover plate which is inclined to the vertical so that the cover plate and parabola contact in a single plane, and a portion of both sides of the width of the parabola is removed, and side sheets are provided to connect the paraboloidal bowl and the cover plate. The exciter is a conical multimode exciter with an aperture angle of about 100.degree. and is provided with at least one and preferably a plurality of concentrically arranged slits on the conical surface of the exciter facing the paraboloidal reflector with the depth of the slits decreasing in a direction toward the edge of the cone adjacent the reflector. The width of the slits is between .lambda./10 and .