Compact Circularly Polarized Slotted Octagonal Microstrip Antenna for X-Band and Satellite Applications

This work introduces a circularly polarized (CP) antenna for X-band applications. The proposed antenna features an octagonal radiating element printed on an FR4 dielectric substrate and fed by a 50 Ω microstrip line. With dimensions of 28×28×1.6 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>, the antenna consists of an octagonal patch integrated with a rectangular slot, enabling operation in the X-band. The design achieves a -10 dB impedance bandwidth of 5.7% centered at a resonant frequency of 8.92 GHz. Additionally, the antenna exhibits CP characteristics, with a 3 dB axial ratio bandwidth of 9.1%, covering the range from 8.7 to 9.5 GHz. This antenna is well-suited for radar and satellite communication applications.