Wideband Circularly Polarized Exponential Slot Antenna with Rectangular Island for X-Band Satellite Applications

This paper introduces a compact, circularly polarized exponential slot antenna with a rectangular island. The concept of the proposed antenna is similar to that of fractal antennas as it is based on designing an asymmetric slot shape with an increased electrical length within a small area, thanks to the exponential path. The obtained results are as follows. The reflection-coefficient |S11| of the proposed antenna covers the band from 5.5 GHz to 9 GHz. The proposed antenna is circularly polarized with an axial-ratio (AR) bandwidth that extends from 6.87 GHz to 8.9 GHz. It offers simultaneous dual circular polarizations (RHCP and LHCP). The gain of the proposed antenna varies between 4.2 dBic and 5.4 dBic. The efficiency reaches 94%. The size of the antenna is compact making it suitable for CubeSats with limited surface area. The proposed antenna intended application is X-band Earth-Space satellite communication. The proposed antenna can be employed for both the X-band satellite downlink (from 7.25 GHz to 7.75 GHz) and uplink (from 7.9 GHz to 8.4 GHz) frequency bands. Additionally, the antenna can be utilized in military applications, and RFID tag tracking equipment. A prototype of the proposed antenna has been fabricated and then measured using Vector Network Analyzer (VNA) and inside an anechoic chamber. The measurement results of the proposed antenna are in excellent match with the simulated ones. © (2024), Electromagnetics Academy. All rights reserved.