Showing papers on "Feed horn published in 1969"

Coaxial-line to waveguide transition for horn antenna

Abstract: THE INVENTION RELATES TO AN ANTENNA ASSEMBLY FOR MICROWAVE USAGE WHICH IS CHARACTERIZED BY A COAXIAL-LINE TO WAVEGUIDE TRANSITION. THE ANTENNA INCLUDES A RECTANGULAR WAVEGUIDE SECTION, A SECTORAL HORN, AND A TRANSFORMER FOR PROVIDING IMPEDANCE MATCHING BETWEEN THE WAVEGUIDE AND THE HORN. THE TRANSITION IS ACCOMPLISHED BY FEEDING TO THE END OF THE WAVEGUIDE AN E-PLANE LOOP, I.E., A LOOP PARALLEL TO THE ELECTRIC FIELD PLANE IN THE WAVEGUIDE. THE END FEEDING OF THE WAVEGUIDE RESULTS IN A MINIMUM VERTICAL DIMENSION OF THE OVERALL DEVICE WHEN THE COAXIAL LINE IS ATTACHED. THE SMALL VERTICAL DIMENSION IS DESIRABLE IN ORDER TO PERMIT STACKING OF A REQUIRED NUMBER OF ANTENNAS IN AN ARRAY HAVING LIMITED SPACE REQUIREMENTS BETWEEN ASSEMBLY INPUTS. THE INVENTION ALSO FEATURES A WIDE BAND RESPONSE.

Diplexer for radio communication

Abstract: A diplexer enabling radio transmitter and receiver to operate simultaneously or sequentially with the same antenna with closely spaced transmitter and receiver frequencies. The diplexer consists essentially of a low pass and notch filter in the transmitter circuit, a band pass filter in the receiving circuit and series coaxial cables of predetermined lengths in the transmitting and receiving circuits which are connected to a common antenna. The electrical length of the coaxial cable in the transmitting circuit is adjusted to be a high impedance to the receiver frequency, whereas the electrical length of the coaxial cable in the receiving circuit is adjusted to be a high impedance to the transmitter frequency. The low pass filter and the receiver band pass filter may be similar to those normally used in radio communication without diplexing. The notch filter is tuned to reject the wave energy generated by the transmitter at the receiver frequency.

Dual frequency band,polarization diverse tracking feed system for a horn antenna

Abstract: THE APPARATUS OF THE PRESENT INVENTION CONSTITUTES A FEED TO A SINGLE HORN-TYPE ANTENNA PROVIDING ONE FREQUENCY AND FOR COMMUNICATIONS AND MONOPULSE TRACKING AND A HIGHER FREQUENCY BAND FOR HIGH POWER TRANSMITTING MORE PARTICULARLY, THE HIGHER FREQUENCY BAND IS OF THE ORDER OF 50-100 PERCENT HIGHER THAN THE FREQUENCY BAND FOR THE RECEIVE AND TRACKING FREQUENCIES. IN THIS LATTER FREQUENCY BAND, THE ANTENNA IS CAPABLE OF RECEIVING COMMUNICATIONS AND HAVING MONOPULSE TRACKING CAPABILITY WITH POLARIZATION DIVERSITY, I.E., OTHOGONAL LINEAR, ORTHOGONAL CIRCULAR, ROTATABLE LINEAR OR ARBITRARY ELLIPTICAL POLARIZATIONS. CROSS-POLARIZATION OF ALL PATTERNS IS VERY LOW AND CROSS-TALK BETWEEN AZIMUTH AND ELEVATION TRACKING CHANNELS IS SUBSTANTIALLY ZERO. ALSO, HIGH EFFICIENCY TRACKING CAN BE ACHIEVED OVER A BROAD FREQUENCY RANGE WITHOUT RETUNING OF COMPONENTS SUCH AS COUPLERS OR FILTERS.

H-plane pattern of a pyramidal horn

Abstract: Edge-diffraction theory is applied to compute the H - plane pattern of a pyramidal horn. Diffracted rays from E edges of the aperture are shown contributing to back-lobe radiation. A back-lobe pattern obtained by using finite current elements is also given. The computed results agree well with measurements.

Diffraction by dielectric-loaded horns and corner reflectors

Abstract: Experimental results for the radiation patterns of sectoral horns and corner reflector antennas loaded with uniform and wedge-shaped dielectric slabs along the walls are presented. The results clearly indicate that it is possible to improve the directivity in all cases without a significant increase in the overall antenna weight.

Proposed high-efficiency spherical-reflector antenna

Abstract: A technique is proposed for raising the efficiency of sphereical-reflector antennas embodying the Gregorian method of phase correction. The method is based on the Galindo-Williams modified Cassegrain antenna. An additional subreflector is introduced between the Gregorian corrector and the spherical reflector, in order to cause the power rom the feed horn to be uniformly distributed over the main reflector aperture. Equations are presented which enable the co-ordinates of the subreflectors to be computed. Two examples are given and a theoretical effieciency of 93% is predicted in one case.

Beam-scanning primary feed for parabolic reflectors

Abstract: A system is described which achieves wide-angle beam scanning from a parabolic reflector antenna by movement of an adaptive primary-feed system about a defined locus. The feed system performs a sampled spatial Fourier transformation of the focal-plane field in order to obtain a uniform power distribution prior to phase compensation and summation. Scanning of ±15 beamwidths with less than 0.5dB loss in gain and negligible beam distortion has been demonstrated experimentally.

Short range microwave system

Abstract: A short range, low power, microwave system for transmitting single channel data (video, audio, computer pulses, etc.) over distances up to approximately one mile at a frequency range of about 12.2 to 12.7 GHZ. The system includes a microwave transmitter wherein the carrier is amplitude modulated by the desired intelligence and a microwave receiver which includes a reflector feed horn, crystal detector assembly, a bias system for the detector and video amplification; the receiver circuit operates to convert the intelligence from the carrier directly into a usable signal without heterodyning.

Antenna and acoustic horn apparatus

Abstract: DISCLOSED ARE ANTENNA AND ACOUSTIC HORN APPARATUS USABLE IN PORTABLE COMMUNICATIONS UNITS, SUCH AS TRANSCEIVERS. ONE SUCH APPARATUS INCLUDES A DIELECTRIC ACOUSTIC HORN POSITIONED WITHIN THE VOLUME OF SPACE BETWEEN TWO PARALLEL PLATES OF AN ANTENNA. THE ACOUSTIC HORN, WHICH TOGETHER WITH THE AIR IN THE VOLUME COMPRISES DIELECTRIC BETWEEN THE ANTENNA PLATES, PROVIDES A PATH OF VARYING ACOUSTIC IMPEDANCE FOR MATCHING THE ACOUSTIC IMPEDANCE OF FREE SPACE TO THE ACOUSTIC IMPEDANCE OF A TRANSDUCER, ALSO INCLUDED IN THE APPARATUS, FOR MORE EFFICIENTLY COUPLING AN ACOUSTIC SIGNAL THEREBETWEEN. AN INDUCTIVE TUNING DEVICE IS CONNECTED BETWEEN THE ANTENNA PLATES TO COMPENSATE FOR THE CAPACITIVE EFFECTS OF ANTENNA DIELECTRIC. OTHER EMBODIMENTS ARE ALSO COVERED.

Investigation of the Rudimentary Horn

Abstract: : The performance of a novel type of antenna named the Rudimentary Horn has been investigated both theoretically and experimentally Detailed experimental investigation of the VSWR properties as well as the radiation characteristics of the antenna has been carried out over the frequency range 1- 10 GHz Over this band of frequencies the antenna has been found to maintain its desirable impedance and radiation characteristics A first order theory has been developed for the radiation field produced by a symmetrical rudimentary horn having exponentially curved radiating elements Fair agreement has been obtained between theory and experiment for the H-plane radiation patterns Further improvement of the theory is desirable The rudimentary horn is found to be a broadband linearly polarized antenna Its cross-polarization response in the direction of the main beam maximum is at least 30 dB down The effects of the variation of the different physical parameters on the performance of the antenna are given General design considerations are also given Possible applications of the rudimentary horn are also discussed In particular, it has been found that in all aspects of electrical performance the rudimentary horn is competitive with commonly used antennas for HF long range communication (Author)