A Tri-Band Shared Aperture Binomial Antenna Array AIR-SAR Applications

An article explores the concept of a shared aperture antenna utilizing a three-band (C/X/Ku) binomial antenna array with linear polarization. The ingenuity lies in coupling three distinct bands within the same aperture, each resonating at different frequencies. Binomial arrays are chosen for their compactness, low polarization, high isolation, and dimensions of
$210\times 60\times 0.8\ \text{mm}^{3}$
. The CST Microwave Studio Simulator is employed to yield results. At the operating frequencies of 5.3 GHz, 9.3 GHz, and 13.265 GHz, the isolation between port-1 and port-2 is −48 dB, between port-1 and port-3 is −58 dB, and between port-2 and port-3 is −57 dB. For the C-band, X-band, and Ku-band, the bandwidth is measured at 0.032%, with a return loss of −15.7 dB. The suggested antenna gains are 13.4 dBi for C-band, 13.7 dBi for X-band, and 13.4 dBi for Ku-band. Furthermore, the antenna exhibits low cross-polarization and strong isolation, surpassing
$25\ dB$
.