Dual‐polarised X‐band patch sub‐array with hybrid feed network for integrated small‐satellite SAR payload

Abstract

A low-profile wideband dual-polarised X-band patch sub-array fed by a hybrid series/parallel network is designed for an integrated small-satellite synthetic aperture radar payload. The experimental results demonstrate that the sub-array, with 1 × 16 patch radiators, fully covers the targeted 9.65 GHz band with 14 dB bandwidths of 9–10.3 GHz for V-polarisation (VP) and 9.3–9.95 GHz for H-polarisation (HP). The isolation between the different feed ports is higher than 36 dB with a peak value of 45 dB. The sub-array achieves cross-to-co-polarisation ratios of below −32 dB within half-power beamwidth scopes of 6° for both HP and VP. The sidelobes maintain −24 dB for HP and −20 dB for VP. The average realised gains are around 17 dBi for both polarisations.