DESIGN AND OPTIMIZATION OF AN ULTRA WIDE BANDIWDTH PHASED ARRAY ANTENNA FOR INDOOR V/UHF RCS MEASUREMENTS

摘要

V/UHF indoor RCS measurements raise many issues in the case where the anechoic chamber dimensions are not large enough compared to the wavelength and the wall absorbers performances are relatively low at these frequencies. Regular transmitting antennas are huge horns with aperture angles which do not eliminate the multi-path signals to and from the target after a reflection on the chamber walls. The purpose of this project was to design a dual polarization wide bandwidth (120 MHz-2000 MHz) phased array antenna with optimized very low side-lobes in the angular direction of the chamber walls. The main constraint of the problem was the handling possibilities in the 36 X 36 X 135 ft anechoic chamber. Therefore the final design had to fit in a 20 X 20 X 3 ft box. The given elementary antenna radiates approximately like a dipole. The main goal on the pattern of the phase array antenna was to create wide bandwidth low levels in the angular directions of the chamber walls. The parameters of the optimization were the size of the antennas, the number of sources, the antenna spacing... The numerical simulations were performed using a Matlab dipoles superimposition based script. This paper details the results of the numerical simulation and a comparison with experimental data.