Design of Millimeter-Wave Low Cross-Polarization Miniaturized Antenna Measurement System Based on Beam Mode Theory

This paper presents a design method of a miniaturized antenna measurement system (MAMS) with low cross-polarization in millimeter-wave band. In this design method, the cause of cross-polarization in the tri-reflector system is analyzed first by using the beam mode theory. Then the geometric structure of the system is determined by using the cross-polarization elimination condition. Furthermore, a MAMS with main aperture size of 0.6 m, feed rotation angle of 30° and the overall structure size of 1.85 m ×0.6 m ×2.16 m is finally realized. The numerical simulation results show that the cross-polarization of the system is less than −40 dB, and the co-polarization amplitude (phase) ripple is within 1 dB (10
^○
) in the frequency range of 100–300 GHz. In addition, the diameter of the quiet zone (QZ) is 0.42 m, and the utilization rate of the QZ can reach over 70%. This design method provides a theoretical reference for the design and construction of a miniaturized high performance antenna measuring instrument with flexibility and mobility.