Concave Serrated-Edge Reflectors for Compact Range With Lower Frequency Limit

Low-frequency limit is the lowest operating frequency of the compact antenna test range (CATR), which is determined by the electrical size of the specifically designed reflector. Due to the existence of edge diffraction, the size of the reflector must be large enough compared to the wavelength to ensure the quality of the quiet zone (QZ), especially at low frequencies. In this article, a concave serrated-edge reflector (CSER) is presented, which can achieve a new low-frequency limit of 15 wavelengths. Keller cone is utilized to analyze the edge-diffracted rays. The lower level of the diffracted field is achieved in the concave serrated design because these undesired fields are controlled away from the QZ. All results show that the performance of the CSER is superior to other serrated ones.