An Ultrawideband Microwave Reflection Sensor for Plasma Environment Data Acquisition

This letter presents the design and validation of an ultrawideband microwave reflection sensor for plasma environment data acquisition. The sensor employs a four-ridged horn antenna covering the 2 GHz to 26.5 GHz frequency band, enabling broadband interaction with plasmas having electron densities in the range of 10¹⁰ cm^-3 to 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 nonintrusive 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.