Dielectric Lens-Type CATR System Using a Serrated Structure for Antenna Radiation Pattern Measurement

Large aperture antennas are used to compensate for high propagation losses in the millimeter wave bands used by Beyond 5G/6G, satellite, and automotive collision prevention radars. The big anechoic chambers required to accommodate Direct Far-field (DFF) measurements can be prohibitively large and expensive. Establishing anechoic chambers and test ranges large enough to accommodate DFF measurements has proven difficult and costly. More recently, however, the characterization of large aperture millimeter-wave antennas and transceivers can be more economically performed utilizing Compact Antenna Test Range (CATR) systems. Unlike traditional large anechoic chamber-based systems that utilize DFF techniques, CATR systems incorporate Indirect Far-Field (IFF) techniques with reflectors to achieve comparable measurements using less space. This translates into smaller and less expensive test systems. However, conventional reflectors used in millimeter-wave CATR chambers can be expensive to manufacture and set up. This paper proposes a more economical dielectric lens that utilizes a Serrated Structure (SS) around the lens to achieve suitable plane-wave characteristics. The dielectric lens was analyzed using the Finite Element Method (FEM) and then manufactured to theoretical dimensions. As a result, it showed Quiet Zone (QZ) characteristics of 1/3 the diameter of the lens. To show that the manufactured lens could be applied to the CATR system, the results of evaluating the radiation pattern of a 1024-element antenna at 30 GHz are shown below.