A Compact Circularly Polarized Antenna for Mobile Satellite Communication Applications

A compact circularly polarized (CP) substrate-based antenna for mobile satellite service (MSS) is presented. The substrate has a metal ground fully covering its bottom, and an L-shaped shorted strip is loaded on its top. The shorting pin, close to the feeding probe, significantly helps reduce the antenna size. Moreover, the top strip is bent into an L shape to obtain good CP fields in the far field. Within a space of $0.15 \lambda_{0} \times 0.1 \lambda_{0} \times 0.03 \lambda_{0}$, the proposed antenna exhibits a −4-dB gain bandwidth of $21 \text{MHz}(1510-1531 \text{MHz})$, which can fully accommodate the $7-\text{MHz}$ L-band MSS requirements.