Ultra‐Compact Slot‐Loaded Cross‐Shaped Dual‐Port Antenna With Intrinsic Isolation and High Front‐to‐Back Ratio for Dedicated Short‐Range Communication Applications

ABSTRACT

A compact dual‐port antenna is proposed for Dedicated Short‐Range Communications (DSRC) operating in the 5.85–5.925 GHz frequency band. The antenna employs a symmetric slot‐loaded cross‐shaped patch configuration with closely spaced central feed points to intrinsically suppress mutual coupling and control surface current distribution. Without using any external decoupling networks, parasitic elements, or complex feeding structures, the proposed antenna achieves high port isolation exceeding 25 dB, reaching approximately 35 dB at the centre frequency of 5.88 GHz. The antenna exhibits an ultra‐compact electrical size of 0.43 λ × 0.43 λ × 0.012 λ on a Rogers RT/Duroid 5880 substrate, making it well suited for space‐constrained DSRC on‐board unit integration. In addition to compactness and high isolation, the antenna demonstrates highly directional radiation characteristics with a measured front‐to‐back ratio of approximately 17.6 dB, which is explicitly quantified and experimentally validated. These attributes—an electrical footprint of 0.43 λ × 0.43 λ × 0.012 λ , measured isolation of approximately 35 dB at 5.88 GHz, a gain of 6.4 dBi, and a front‐to‐back ratio of 17.6 dB collectively make the proposed antenna a practical and self‐contained solution for DSRC on‐board unit deployment in vehicular and point‐to‐point communication platforms.