Feed horn

About: Feed horn is a research topic. Over the lifetime, 2395 publications have been published within this topic receiving 26548 citations. The topic is also known as: feedhorn.

Design of a Broadband Cosecant Squared Pattern Reflector Antenna Using IWO Algorithm

Abstract: A cosecant squared pattern reflector antenna fed by a pyramidal double-ridged horn for 2-18 GHz is presented. Invasive weed optimization (IWO) algorithm is used for synthesizing the point source doubly curved reflector antenna. IWO method makes antenna synthesis flexible to achieve extra desired features such as low side lobe level (SLL) and low ripples in the shaped beam region. The simulation results via FEKO software package further prove the validity and versatility of this technique for solving reflector synthesis problems. In addition, experimental investigations are conducted to understand the complete reflector antenna system behaviors. Good agreement between the simulation and measurement has been achieved. The ripple in the cosecant squared region and the SLL is less than 1.5 dB and 25 dB, respectively. Based on the obtained results, the proposed reflector antenna can be used in broadband surveillance-search radar systems.

Radio frequency beam forming network

Abstract: A radio frequency beam forming network is disclosed wherein a plurality of antenna feed elements arranged in the focal plane of a radio frequency lens is coupled to corresponding input ports of a radio frequency energy distributing means. Output ports of such radio frequency energy distributing means are coupled to a receiver/transmitter through different paths. Disposed in the different paths are active elements, including variable phase shifters and attenuators. The active elements, in response to control signals, provide proper attenuation and phase shift to the signals passing therethrough thereby to form a desired antenna beam. Such antenna beam is comprised of one or more "spot" beams. With such arrangements failure of a single one of the active elements will only slightly degrade system performance without resulting in a complete loss of any one of the "spot" beams.

Design and analysis of a multimode feed horn for a monopulse feed

Abstract: The design of a multimode feed horn for use in a monopulse feed system is summarized. Both amplitude and phase patterns have been obtained and compared with measurements. The far-field amplitude and phase patterns are computed in consideration of achieving the desired aperture distributions for the sum and difference beams. The phase center of the horn is discussed in relation to the multimode excitation and frequency dispersion. It is shown that the phase center location moves as the mode content changes, and proper adjustment of the mode content will result in design optimization. Some tradeoff curves are also presented for design optimization. >

A way to improve the field of view of the radiotelescope with a dense focal plane array

Abstract: We consider a problem of increasing the field of view (FOV) of the radio telescope by means of multi beam performance of the prime focus hybrid reflector systems. It was shown that array feeds of waveguide and horn elements currently used cannot provide closely spaced beams over a wide FOV and a high aperture efficiency in each beam due to the element spacing restrictions imposed by a size of the element aperture. We proposed a feed design in a form of an integrated dense array with a small physical size of the grid element and a volumetric form of the array element. For the feed, the original excitation system of the array elements has been developed to perform the desirable beam illumination pattern with low spillover level. The results have been obtained both for theoretical and experimental radiation patterns of the array feed. Scanning and multi beam capabilities and limitations of the hybrid reflector antenna have been investigated on the basis of the focal field distribution analysis. As an example, 0.35 F/D ratio reflector (Westerbork Telescope) has been considered. It has been shown that the proposed array antenna is a good candidate be used as the feed to improve the properties of source images by the reflector systems and therefore to increase the FOV of the radio telescope.

Apparatus method and computer program for configurable radio-frequency front end filtering

Abstract: A radio use case is determined for concurrently operating radios of a multi-radio device and/or transmitter and receiver of a FDD radio. A local memory is accessed with the determined use case to find a high and/or a low frequency cutoff for the concurrent operation radio or transmitter/receiver. Control signals are applied to impose the high and/or the low frequency cutoff to a pair of frequency adjustable diplexers that are in series with one another in one of a transmit branch or a receive branch of a duplexer circuit that is disposed between the radio and an antenna. Then, a receive signal is passed through the antenna and the receive branch of the duplexer circuit to the radio or receiver of the FDD radio, or a transmit signal is passed from the respective radio or transmitter of the FDD radio through the transmit branch of the duplexer circuit to the antenna.