A Circularly Polarized Broadband Composite Spiral Antenna for Ground Penetrating Radar

To enhance the capability of a ground penetrating radar (GPR) in subsurface target identification and improve its polarization sensitivity in detecting underground linear objects, a circularly polarized broadband composite spiral antenna was designed. This antenna integrates equiangular spiral and A...

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Bibliographic Details
Main Authors: Hai Liu, Shangyang Zhang, Pei Wu, Xu Meng, Junyong Zhou, Yanliang Du
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Sensors
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Online Access:https://www.mdpi.com/1424-8220/25/6/1890
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Summary:To enhance the capability of a ground penetrating radar (GPR) in subsurface target identification and improve its polarization sensitivity in detecting underground linear objects, a circularly polarized broadband composite spiral antenna was designed. This antenna integrates equiangular spiral and Archimedean spiral structures, achieving a wideband coverage of 1–5 GHz with stable circular polarization characteristics. The antenna employs an exponentially tapered microstrip balun for impedance matching and a metallic-backed cavity filled with absorbing materials to enhance its directivity. Experimental results demonstrate excellent radiation performance and stable circular polarization characteristics, with the axial ratio consistently below 3 dB throughout the operating frequency band, highlighting its suitability for polarimetric GPR systems. Furthermore, a 3D GPR measurement using the designed antenna validates its improved capacity for detecting subsurface linear objects, compared to the conventional linearly polarized bowtie antenna.
ISSN:1424-8220