A Foldable Antenna Booster for Smartphone Satellite Communication Inspired by Polarization Converter

This paper presents a foldable antenna booster (AB) for enhancing smartphone satellite communication. The design utilizes a polarization converter placed above the smartphone’s top metal frame antenna (TMFA) to convert its linear polarization (LP) radiation into circular polarization (CP). The converter is an inclined dipole, and a back cavity with two parasitic patches is introduced to improve CP gain and bandwidth. The compact design of the AB allows it to be folded into a small size (75.3 × 75.3 × 3.5 mm³) for easy storage, enhancing portability. In its working configuration, the AB has a larger volume but significantly improves communication performance. Experimental results show the AB provides a wide operating bandwidth of 1.92-2.29 GHz, covering the Tx and Rx bands of the Tiantong satellite, with an efficiency exceeding 70%. The CP gain is increased by up to 7 dB, making the AB a highly efficient solution for smartphone satellite communication. This work demonstrates a simple, effective foldable structure that significantly improves the practicability of satellite communication on smartphones.