The Design Of Tri-Reflector Compact Antenna Test Range

Compact Antenna Test Range(CATRs) are of importance in antenna testing and radar cross section testing, which offer effective ways for testing antennas operating in high frequency, millimeter wave and sub-millimeter wave antennas, etc. Dual-reflector feed system, including one feed horn and two shaped reflectors, are implemented in the Tri-reflector CATR. The modification can (1)enlarge the quiet zone size and obtain higher quiet zone usage than the popular ones do, (2)better control the beam shape and improve quiet zone quality, (3)reduce the cost and difficulty of manufacture.Geometrical Optic method is utilized in the synthesis process, applying conservation of power and phase condition. The process starts from optical center of shaped reflectors and extrapolates the subsequent points using theory of kinematic and dynamic ray tracing. Reflectors curvature parameters are obtained by the design method, as well as the system structure. The CATR system would generate pseudo plane wave after the collimation of reflectors.To verify the design method,2 types of tri-reflector CATR are simulated and analyzed. We emphasis on its output field and quiet zone, and do study on factors that affect the quiet zone.