Dual-Frequency Common-Cable Waveguide Slot Satellite Communication Antenna

A marine cable-conformal dual-band omnidirectional circularly polarized waveguide slot antenna is proposed for L/S-band (1.59–1.84 GHz/2.48–2.55 GHz) maritime satellite systems. Axially symmetric X-shaped slots enable dual-band operation with 14.6% impedance bandwidth (L-band) and axial ratio < 3 dB. A three-stage tapered coaxial feeding network achieves efficient matching (|S11| < −10 dB) across a BeiDou-1 uplink (1.61–1.6265 GHz) and downlink (2.4835–2.5 GHz), delivering 4.1 dBi peak omnidirectional gain at 1.6 GHz. The compact design (radial dimension ≤ 0.25λ) offers robust performance in harsh marine environments with integrated wideband, high-gain, and conformal capabilities.