Secure Pinching Antenna-aided ISAC

In this letter, a pinching antenna (PA)-aided scheme for establishing a secure integrated sensing and communication system (ISAC) is investigated. The underlying system comprises a dual-functional radar communication (DFRC) base station (BS) linked to multiple waveguides to serve several downlink users while sensing a set of malicious targets in a given area. The PA-aided BS aims at preserving communication confidentiality with the legitimate users while being able to detect malicious targets. One objective of the proposed scheme is to optimize the PA locations, based on which an optimal design of the legitimate signal beamforming and artificial noise covariance matrices is provided to maximize the network's sensing performance, subject to secrecy and total power constraints. We demonstrate the efficacy of the proposed scheme through numerical examples and compare that against a traditional DFRC ISAC system with a uniform linear array of half-wavelength-spaced antennas. We show that the proposed scheme outperforms the baseline PA-aided scheme with equidistant PAs by $3$ dB in terms of illumination power, while it can provide gains of up to $30$ dB of the same metric against a traditional ISAC system with half-wavelength-space uniform linear arrays.