Multiport Shared Aperture Antenna for S/X-Band SAR Applications

This paper presents designing a single layer dual band dual polarized (DBDP) series-fed shared aperture antenna (SAA) for S/X-band applications. X-band antenna is designed with the concept of series-fed 4-group 2×2 planar arrays along with integration of 2-way power divider in both vertical and horizontal polarizations for combined gain enhancement. To verify the antenna design concept, a prototype is fabricated and measured both S-Parameters and radiation characteristics including gain measurements. Return loss| S11|>-10dB the antenna covers from 3.12-3.42GHz (9.3% BW) in S-Band and 9.2-9.36GHz (1.72
^%
BW) in X-band. The measured isolation| S21| between two different bands in the same polarization is better than 25 dB and isolation between two different bands in two orthogonal ports is better than 30 dB. Measured gain of the antenna at S-band is better than 8.5dBi at SV-Port and SH-Port and X-band is better than 13dBi at XV1 & XV2 ports and XH1 & XH2-ports.