Cassegrain antenna

About: Cassegrain antenna is a research topic. Over the lifetime, 3207 publications have been published within this topic receiving 28278 citations.

A Novel Inverted Trapezoidal Antenna Fed by a Ground Image Plane and Backed by a Reflector

Abstract: This paper presents a new ultrawide band inverted trapezoidal antenna. The antenna is fed by a 50 ? coaxial cable through an image ground plane and backed by a reflector for the radiation and detection of ultra-short electrical pulses. A 50 ? input impedance was achieved over a wide bandwidth by the use of a 3D microstrip line feeding concept. The input bandwidth of the antenna was calculated from simulation and verified by experiment to be more than 4 GHz. The metallic reflector is introduced to eliminate radiation back lobes. Maximum pulse radiation occurs at an elevation angle of 40° and 60° for broadside and edge radiation, respectively.

Automatic Satellite Tracking System

Abstract: A satellite tracking system for tracking a synchronous satellite includes a satellite antenna system movably supported on a roof of a vehicle via a roof frame to move between an operation position and a folded position. At the operation position, the satellite antenna system is rotated on the roof frame to adjust a horizontal orientation of a parabolic reflector of the satellite antenna system while the parabolic reflector is pivotally lift at a predetermined inclination angle to align with the satellite. At the folded position, the parabolic reflector is pivotally dropped down until the parabolic reflector faces downwardly to the roof of the vehicle to conceal a signal transmitting device of the satellite antenna system between the parabolic reflector and the roof of the vehicle. Therefore, the satellite antenna system provides a relatively low profile at the folded position when the vehicle travels.

Simultaneous multi-band ring-focus reflector antenna-broadband feed

Abstract: Compact multi-band antenna system (500) includes a main reflector (502) having a shaped surface of revolution about a boresight axis of the antenna operable at a plurality of frequency bands spectrally offset frcm each other. A multi band feed system (300) is provided for the main reflector that includes a subreflector (304) formed as a shaped surface of revolution about the boresight axis of the antenna, and a horn antenna (302). The horn antenna has one or more ridges (312) disposed in a throat region (314) of the horn antenna extending in a direction aligned with the boresight axis (3100 of the antenna. The horn antenna is coupled to the shaped surface of revolution defining the subreflector.

Reflector antennas for microwaves

Abstract: A dual-reflector microwave antenna includes a main reflector having a shape that is a portion of a paraboloid generated by revolution of a parabola around having a single, common axis of rotation and symmetry. A primary feed extends along the axis of the main reflector on the concave side of the main reflector, and a subreflector located beyond the end of said primary feed has an image-inverting surface configuration that has a ring focus located between the main reflector and the subreflector and extending around the axis of the main reflector. In either a single or dual-reflector antenna, the main reflector has a shield with a band of dielectric or conductive material extending around at least a portion of the inner surface of the shield for reducing the return loss of the antenna. Patterns may be improved by providing a shield of absorber material extending around the outer periphery of at least an end portion of the primary feed. In the case of a dual-reflector antenna, return loss may be reduced by providing a dielectric or electrically conductive element between the primary feed and the subreflector, and/or by providing an annulus of absorber material on the surface of the subreflector.

Efficient computation of the far field of parabolic reflectors by pseudo-sampling algorithm

Abstract: The newly developed pseudo-sampling representation is applied for computing the far field of an offset parabolic reflector with a cluster feed illumination. A new comb-type fast Fourier transform (FFT) algorithm is used in a computer program. Both precision and computational time are analyzed, demonstrating the excellent performance of the method.