Contents I. Introduction
Blended rolled edge reflectors were introduced a couple decades ago [1], [2]. They are known for offering better diffraction characteristics in the front of reflectors, which allow them producing a smoother quasi-plane wave in the so-called quiet zone of compact antenna test ranges (CATR) [3]. CATRs are widely used in antenna measurements since the early ‘70s [4]. During those years workers have been searching for methods to improve their performance. Less rippled and smoother field distribution (magnitude and phase) in a quiet zone (QZ) offers not only better representation of a quasi-planar wave, but usually increases the size of such zones. In order to achieve these improvements, several methods had been proposed. All of them are based on the idea of decreasing diffraction from the edges of reflector antennas. One of the most well-known methods introduces so-called serrated edges to the reflector [5], [6]. This seeks to avoid coherent superposition of diffracted waves illuminated by reflector edges. The configuration also offers rather nice diffraction pattern on the anechoic chamber walls. However, it usually produces rather rippled field amplitude and phase in the quiet zone. In order to reduce ripples within the QZ, the blended rolled edge (BRE) reflector concept was resurrected. Due to much higher computational power and dramatically improved commercial computational electromagnetic (CEM) software, it has become possible to solve such complex geometries with a very high accuracy without spending extended time in simulations. Moreover, full optimisation of these structures has become possible in very reasonable run-times requiring only comparatively moderate computational resources.
