Abstract: A microwave antenna for use in a sectorized cellular communication system comprises a wide-flare pyramidal horn having two pairs of opposed flared side walls. At least one of the two pairs of opposed walls has corrugated interior surfaces. The length of the horn and the flare angle of the walls having the corrugated interior surfaces are selected to produce a ratio &Dgr;e/&lgr; greater than 1.5, where &Dgr;e/&lgr;=[a/(2/&lgr;)] tan (&agr;e/2) is the spherical-wave error of said horn, &lgr; is the free space wavelength of the microwave signals to be transmitted by said antenna, &agr; is the horn's aperture width, and &agr;e the half-angle of the horn in the horizontal plane.

Abstract: A hog-horn antenna for producing two orthogonally polarized signals. The elevation plane pattern of each signal can be made to have virtually any shape, but is typically of a substantially cosecant-squared shape. In providing for the dual-polarization capability, the hog-horn antenna is designed to produce substantially equal gains for orthogonal polarizations, either simultaneously or separately. Two techniques to substantially equate the elevation plane radiation patterns of the two polarizations include corrugating or absorber-lining the surfaces of portions of the hog-horn antenna. Azimuthal pattern control may be achieved by corrugated/absorber lined flanges.

Abstract: A microwave antenna for use in a sectorized cellular communication system comprises a wide-flare pyramidal horn having two pairs of opposed flared side walls. At least one of the two pairs of opposed walls has corrugated interior surfaces. The length of the horn and the flare angle of the walls having the corrugated interior surfaces are selected to produce a ratio &Dgr;e/&lgr; greater than 1.5, where &Dgr;e/&lgr;=[&agr;/(2/&lgr;)] tan (&agr;e/2) is the spherical-wave error of said horn, &lgr; is the free space wavelength of the microwave signals to be transmitted by said antenna, &agr; is the horn's aperture width, and &agr;e the half-angle of the horn in the horizontal plane.

Abstract: A hog-horn antenna for producing two orthogonally polarized signals. The elevation plane pattern of each signal can be made to have virtually any shape, but is typically of a substantially cosecant-squared shape. In providing for the dual-polarization capability, the hog-horn antenna is designed to produce substantially equal gains for orthogonal polarizations, either simultaneously or separately. Two techniques to substantially equate the elevation plane radiation patterns of the two polarizations include corrugating or absorber-lining the surfaces of portions of the hog-horn antenna. Azimuthal pattern control may be achieved by corrugated/absorber lined flanges.

Abstract: A radiating coaxial cable having a longitudinal axis comprises an inner conductor having a longitudinal axis wherein the axis of the inner conductor defines the axis of the cable. A dielectric material surrounds the inner conductor. A continuous outer conductor surrounds the dielectric in direct contact therewith and is spaced from the inner conductor. The outer conductor has a plurality of slots disposed therein. Adjacent slots are spaced in the axial direction a distance S. One or more adjacent slots are grouped together in a cell. The cable has a plurality of cells. Adjacent cells are angularly disposed from each other by an angle &agr;.

Abstract: A dual-reflector microwave antenna comprises the combination of a paraboloidal main reflector having an axis; a waveguide and dual-mode feed horn extending along the axis of the main reflector, a subreflector for reflecting radiation from the feed horn onto the main reflector in the transmitting mode, and a shield extending from the outer edge of the main reflector and generally parallel to the axis of the main reflector, the inside surface of the shield being lined with absorptive material for absorbing undesired radiation. The subreflector is shaped to produce an aperture power distribution that is substantially confined to the region of the main reflector outside the shadow of the subreflector. The support for the subreflector is preferably a hollow dielectric cone having a resonant thickness to cause energy passing through said cone to be in phase with energy reflected off of said cone so as to achieve phase cancellation.

Abstract: An omnidirectional microwave antenna comprises a paraboloidal reflector disposed above the ground and facing downwardly with a substantially horizontal aperture and a substantially vertical axis. A vertically oriented feed horn is located below the paraboloidal reflector on the axis of the paraboloidal reflector and has a phase center located near the focal point of the paraboloidal reflector. A conical reflector having a shaped reflecting surface defined by the parameters of a mathematical equation extends downwardly away from the periphery of the feed horn for reflecting radiation received vertically from the paraboloidal reflector in a horizontal direction away from the conical reflector, and for reflecting horizontally received radiation vertically to the paraboloidal reflector.

Abstract: An omnidirectional microwave antenna comprises a paraboloidal reflector disposed above the ground and facing downwardly with a substantially horizontal aperture and a substantially vertical axis. A vertically oriented feed horn is located below the paraboloidal reflector on the axis of the paraboloidal reflector and has a phase center located near the focal point of the paraboloidal reflector. A conical reflector having a shaped reflecting surface defined by the parameters of a mathematical equation extends downwardly away from the periphery of the feed horn for reflecting radiation received vertically from the paraboloidal reflector in a horizontal direction away from the conical reflector, and for reflecting horizontally received radiation vertically to the paraboloidal reflector.

Abstract: A radiating coaxial cable comprises an inner conductor, a layer of cellular foam dielectric material surrounding the inner conductor, and a single, continuous, corrugated outer conductor surrounding the dielectric foam layer in direct contact with it. The outer conductor forms at least one row of slots which are configured to produce a radiated field polarized perpendicularly to the axis of the cable to substantially avoid the radiation of a field polarized parallel to the axis of the cable and to provide coupling energy between the interior of the cable and the slots. In this way a substantially constant near-field pattern is produced along the length of the cable across the bandwidth of the cable.

Abstract: A radiating waveguide comprises an elongated waveguide with a transverse cross-section dimensioned to carry only the dominant mode at a selected operating frequency. One wall of the waveguide forms a continuous non-resonant longitudinal slot or equivalent thereof to produce a radiated field polarized perpendicularly to the slot. The slot extends substantially parallel to the axis of the waveguide and has a transverse dimension that is sufficiently narrow to substantially avoid the radiation of a field polarized parallel to the slot.

Abstract: An overmoded waveguide transition comprises a flared waveguide section having different transverse cross-sections at opposite ends thereof, the longitudinal shape of a section of the transition adjacent an end thereof being defined by the equation:(r.sup.p /a)-(l.sup.p /b)=1where a and b are constants, r is the radius of the transition, l is the axial distance along the transition measured from one end, and the exponent p has a value greater than two.

Abstract: A microwave antenna comprising the combination of a paraboloidal main reflector; a subreflector located such that the paraboloidal main reflector and the subreflector have a common focal point lying between the main reflector and the subreflector; a feed horn for transmitting microwave radiation (preferably symmetrically) to, and receiving microwave radiation from, said subreflector; and a shield connected to the peripheral portion of the subreflector and having an absorbing surface which reduces side lobe levels both by capturing the feed horn spillover energy and by reducing the diffraction of microwave radiation from the edge of the subreflector. The shield is preferably formed as a continuous axial projection extending from the periphery of the subreflector toward the main reflector substantially parallel to the axis of the feed horn. The reflective surface of the subreflector is suitably a section of an approximate ellipse.

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: A phased-overmoded, tapered waveguide transition has a central section which is tapered linearly in the longitudinal direction and two end sections which are tapered curvilinearly in the longitudinal direction. One of the end sections and at least a portion of the other end section are overmoded and, therefore, give rise to higher order modes of the desired microwave signals propagated therethrough. The lineraly tapered central section shifts the phase of higher order modes generated at one end of the transition so that at least a major portion of such higher order modes is cancelled by higher order modes generated at the other end of the transition.

Abstract: A horn-reflector microwave antenna has a reflector plate which is a section of a paraboloid, and a flared feed horn for supplying microwave signals to the reflector plate. The horn has a conical section forming a circular aperture at the wide end, which is the end closer to the reflector plate, and a pyramidal section forming a square aperture at the narrow end, which is the end farther away from the reflector plate. Microwave signals are supplied to the feed horn with the electrical field extending along a diagonal of the square aperture.

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.