An Ultra-Wideband Microwave Reflection Sensor for Plasma Environment Data Acquisition

This letter presents the design and validation of an ultra-wideband microwave reflection sensor for plasma environment data acquisition. The sensor employs a four-ridged horn antenna covering the 2–26.5 GHz frequency band, enabling broadband interaction with plasmas having electron densities in the range of 10¹⁰–10¹² cm⁻³. The antenna structure integrates high-temperature-resistant materials, allowing stable operation under thermal conditions up to 1000 K. Reflection measurements and full-wave simulations are performed under multiple plasma environments to evaluate the sensor's response characteristics. The results indicate that the proposed design enables non-intrusive and broadband acquisition of reflection data in varying plasma conditions. This approach provides a viable solution for in-situ sensing of plasma environments in high-speed aerospace and other demanding conditions.