The interpanel gap scattering effect in a compact range

Abstract

Abstruct-In recent years, the compact range has become a popular measurement tool in the evaluation of microwave antennas. This trend leads to the use of larger reflectors over larger frequency bands. Those reflectors can be built to the required accuracies, hut they have to be assembled from many panels which introduce interpanel gaps. The electromagnetic scattering produced by the gaps affects the uniformity of the field in the quiet zone of the compact range. An analytical approach coupled with experimental determination of a key parameter has been developed to quantify the effect of the scattering from the interpanel gaps in a compact range. The results show the significance of this effect on the copol and x-pol distribution in the quiet zone area.

Characteristics of Dual Reflector Antennas With Gaps Between the Panels Forming the Subreflector: MOM and PO Analysis

“…Inter-panel gaps on a single reflector system has been studied using PTD ILDC [6] and compared with Method of Moments (MoM). In a separate study in [8], inter-panel gap scattering effect from single reflector compact range is also examined via approximation of equivalent magnetic current placed at gaps locations. Moreover in [7], an extension of PO current is considered by introducing slot magnetic fringe currents along the slots between the panels in addition to incorporating fringe currents at the reflector rim.…”

“…Contribution of slot and rim fringe currents in [7] has primarily affected cross-polarization field which are recorded typically about 40 dB below the main beam. Although never explicitly stated in [6][7][8], all papers have made the assumption that panel displacements on the reflector surface are in alignment with the trajectory of the ideal reflector (these type of panel alignment will later be classified as lateral panel displacement).…”