An SDR-Integrated Dual-Band Directional Antenna System for Counter-Drone RF Link Suppression: Design and Open-Field Validation

Abstract

This paper presents a single-fed dual-band stacked antenna developed for directional counter-drone RF link suppression at the 2.45 GHz and 5.8 GHz ISM bands. The proposed antenna combines a partial ground structure, a metallic reflector, two circular parasitic-resonator layers, and a frequency-selective surface within an air-spaced multilayer configuration. A single coaxial probe excites both operating bands without requiring a complex feeding network. The fabricated prototype exhibits measured −10 dB impedance bandwidths of 2.28–2.52 GHz and 5.60–5.92 GHz. Far-field measurements yielded gains of 9.64 dBi at 2.45 GHz and 12.06 dBi at 5.8 GHz, compared with simulated values of 10.00 and 12.50 dBi, respectively. Additional in-band measurements showed simulation-to-measurement gain differences below 0.7 dB, while the measured co-polarized radiation patterns preserved the predicted broadside directional behavior. The prototype was subsequently integrated with a BladeRF 2.0 Micro xA9 software-defined radio platform. Commercial-drone tests conducted at 2.4 GHz demonstrated observable interruption of the tested video-transmission and command-control links. In the repeated 2.4 GHz antenna-level comparison, loss of live-video updating was observed in 4/4 trials with the proposed DBSA and in 0/4 trials with a commercial 5.5 dBi reference antenna at a 20 m horizontal antenna-to-target separation. A complementary open-field FPV video-link test at 5.8 GHz, conducted using the same antenna-to-target geometry, employed a 30 MHz broadband suppression waveform and produced severe visible video degradation without complete link interruption. The results demonstrate experimentally validated antenna–SDR integration at both operating bands; however, the SDR experiments represent application-level proof-of-function observations rather than calibrated suppression thresholds, maximum operational ranges, or validation of a complete counter-drone jammer system.