Development of Array Triangular Microstrip Antenna for Circularly Polarized-Synthetic Aperture Radar

Circularly Polarized Synthetic Aperture Radar is an active remote sensing system that employs left- and right-handed circular polarization to enhance Earth observation capabilities. By operating in the C, S, and L frequency bands, Circularly Polarized Synthetic Aperture Radar enables the generation of axial ratio, ellipticity, and tilt angle images, thereby improving information extraction and overcoming conventional Synthetic Aperture Radar limitations such as high-power consumption, Faraday rotation sensitivity, backscatter distortion, and low target discrimination. In this study, we propose and investigate triangular microstrip array antennas as the core radiating elements for Circularly Polarized Synthetic Aperture Radar applications in the L-bands and C-bands. Designed for integration into Low Earth Orbit microsatellites and Unmanned Aerial Vehicles, these antennas provide notable advantages including compactness, light weight, conformability, cost-effectiveness, and ease of integration with other circuits. Numerical simulations, supported by partial experimental validation, confirm that the proposed antennas achieve adequate gain, axial ratio bandwidth, beamwidth, and efficiency. These results demonstrate that triangular microstrip arrays can fulfill the technical requirements for Circularly Polarized Synthetic Aperture Radar implementation on Low Earth Orbit and Unmanned Aerial Vehicle platforms, offering a promising solution for advanced, low-cost remote sensing systems.