A Novel Shaping Design Technique for the Reflector in Hybrid Antennas

Abstract

A new reflector shaping technique to improve the beam scanning capability of hybrid antennas (i.e., a reflector system illuminated by a phased array) is presented. Errors between the desired scan directions and the outgoing rays' directions in the scanning range are minimized by adjusting the reflector shape. This technique can be used to decrease the active element number of the feed array during the antenna scans, or reduce the gain loss caused by beam scanning when the number of active elements is given. An offset reflector antenna system is designed and analyzed, through which the validity of the technique is demonstrated.

Reflector antenna shaping by regularized B‐spline in conjunction with one‐sided least square optimization

“…Over the past several decades, reflector shaping has been the preferred technology to provide uniform gain throughout a certain geographical area in antennas of geostationary satellites 1–10 . In this technique, the surface of the reflector is usually defined using a combination of a base surface such as paraboloid and a distortion, which is an expansion of a set of orthogonal functions 1,5–13 . Among the possible choices of orthogonal function expansion, B‐spline polynomials have been widely used 6,10 .…”

“…[1][2][3][4][5][6][7][8][9][10] In this technique, the surface of the reflector is usually defined using a combination of a base surface such as paraboloid and a distortion, which is an expansion of a set of orthogonal functions. 1,[5][6][7][8][9][10][11][12][13] Among the possible choices of orthogonal function expansion, B-spline polynomials have been widely used. 6,10 The expansion coefficients are optimized such that performance requirements are satisfied.…”