Cassegrain Reflector Antenna Design consists of various effects caused by blockage and its effect on overall performance. The design for minimum blockage condition results in geometry that offers lower amount of blockage and increased spillover past the subreflector. To avoid this, optimized design of the antenna results in geometry that offers lower amount of spillover past the edges of the ma...

We define here a new symmetry operator called reciprocation. Apertures that remain unchanged afler reciprocation are called self-reciprocal, and have a number of unique properties. When excited suddenly by a voltage, a self-reciprocal aperture becomes an antenna. This antenna is an approximation to a TEM horn, to a lens IRA (TEM feed + lens), or to a reflector IRA (TEM feed + reflector). Becaus...

A design methodology for collapsible rib-tensioned surface (CRTS) reflectors is presented. Offset configurations are explicitly addressed. For a reflector with aperture of 10 m diameter and focal length of 7.8 m, a root-mean-square surface accuracy of about 2 mm is achievable; this result scales linearly with the diameter. The design of a 1.5 m diameter prototype is presented, and the accuracy ...

This paper investigates a 220 GHz quasi-optical antenna for millimeter-wave wireless power transmission. The consists of an offset dual reflector, and fed by Gaussian beam that is based on the output characteristics high-power radiation source-gyrotron. design parameter carried numerical code geometric optics vector diffraction theory. To realize long-distance energy transmission, divergence an...

A novel idea of a realization a Synthetic Aperture Radar (SAR) system combining a reflector antenna with a digital feed array was suggested for the first time in [1]. The new digital beam-forming (DBF) SAR architecture has better overall system performance while being of lower complexity level as compared to the planar antenna based architecture [2]. This innovative idea has driven intensive st...

Dual reflector antennas are considered as pencil beam antennas that can produce radiation identical to searchlight. Cassegrain Reflector Antenna Design consists of various effects caused by blockage by primary feed or by the subreflector and its effect on overall performance. The objective of the paper is to provide the overview of the designing approach that is used to design the axially symme...

I present two methods for constructing angle gathers in 3-D seismic imaging by downward extrapolation. Angles in angle gathers refer to the scattering angle at the reflector and provide a natural access to analyzing migration velocity and amplitudes. In the first method, angle gathers are extracted at each downwardcontinuation step by mapping transformations in constant-depth frequency slices. ...

Abstract— Equivalent charge method is used to design ultra wide band asymptotic conical dipole (ACD) antenna. Combination of linear charge density and point charges is used to generate different profiles for ACD antennas. Two different profiles of ACD antenna are used as a feed for reflector based impulse-radiating antennas (IRAs). This paper focuses on the selection of ideal ACD profile as wel...

P2ww'd'el e @@& .4 paraboloidal reflector antenna fed by a pyramidal horn has found widespread application in radar and communication engineering. However, the reflector antenna has very useful characteristics when it is fed or illuminated by two or four-conductor transmission lines. We have am.lyzed, designed, fabricated, and tested a reflector antenna fed by a pair of conical transmission Iin...

The gravity deformations of the ATCA main reflector, as well as the displacements in the sub-reflector and feed, have been surveyed at a set of elevations by VMS (AT 39.3/109). In this report, I quantify these deformations and displacements and examine their effects on the antenna performance at 90 GHz. I have computed the far-field radiation pattern at each of the survey elevations and the ele...