Design of Dual-Polarized Monopulse Cassegrain Antenna for W-Band Millimeter-Wave Seeker

Abstract In this paper, dual-polarized monopulse cassegrain antenna for W-band millimeter-wave seeker was proposed and the performances were verified by the measured results of the fabricated antenna. Dual-polarized monopulse Cassegrain antenna consists of main/sub- reflector, dual-polarized feed horn and monopulse comparator. The proposed feed horn has 2×2 array square waveguide feeding structure to make monopulse signals and it was designed using 90 degree rotational symmetric structure to receive dual-polarized signals. At the sum and difference channel, the measured vertical and horizontal polarization radiation pattern were similar. Measurement gains are 35.1 dBi for v-pol. and 35.6 dBi for h-pol. at the center frequency with 0.5dBi difference between each polarization and the side lobe level is below 21.6 dB. Key words: Cassegrain Antenna, Monopulse, Dual Polarization, Feed Horn LIG lu001em(LIG NEX1) *n u0011oB?u0019.pqo:ru0015st0quvDw(Department of Electrical and Computer Engineering, INMC, Seoul National University) Manuscript received February 22, 2016 ; Revised March 4, 2016 ; Accepted March 7, 2016. (ID No. 20160222-020)Corresponding Author: Jong-Gyun Baek (e-mail: jonggyun.baek@lignex1.com)