A new cavity-backed sinuous antenna for microwave imaging applications

This study presents the design and analysis of a dual linear polarized sinuous antenna (DLPSA) optimized for ultra-wideband applications, such as remote sensing of longitudinal metallic targets and microwave imaging systems. The capability of the sinuous antenna to generate dual linearly polarized radiation patterns makes it a strong candidate for these applications. A key design challenge lies in developing a practical feeding network that requires modifications to the antenna feed region. The proposed DLPSA antenna achieves unidirectional radiation patterns in the 2–5 GHz frequency band. A prototype was fabricated, with measured results closely aligned with the simulations. The antenna demonstrates enhanced return loss, gain, and radiation pattern performance compared to existing designs. Additionally, the dual linear polarization capability was verified through co- and cross-polarization measurements conducted in an anechoic chamber.