SLM Printed Dual-Band Dual-Polarized Shared-Aperture Filtering Antenna Array for Millimeter-Wave Integrated Sensing and Communication

A 3-D-printed dual-band dual-polarized (DBDP) shared-aperture 1×8 antenna array with filtering response is proposed for millimeter-wave (mm-Wave) integrated sensing and communication (ISAC) systems. The stepped horn is designed first to achieve shared-aperture DBDP radiation. To realize fixed beam radiation for communication purposes, an integrated 1-to-8 filtering network is designed to feed the horns in the high band (HB). To enable a phased scanning array for detection in the low band (LB) with excellent out-of-band suppression, a compact spoof surface plasmon polaritons (SSPPs) filter is studied to feed the individual radiating horn. Selective laser melting (SLM) is employed to monolithically fabricate a 1×8 prototype for demonstration. The measured results demonstrate the operating bandwidths (return loss > 10 dB) of 23.7-26.6 GHz and 28.0-30.4 GHz, respectively, with cross-band isolation higher than 60 dB. The maximum gains of 18.2 and 20.5 dBi are achieved within the operating band, respectively, and the out-of-band gain decays more than 20 dB/GHz. A beam-scanning range of ±47° is achieved in the LB with vertical polarization (VP), while a fixed beam radiation is realized in the HB with horizontal polarization (HP). The proposed design shows great potential for application in future mm-Wave ISAC systems.