A Low-Power Tunable Frequency Selective Surface for Multiplexed Remote Sensing

• Main Authors: Ronald P. Jenkins, Micah D. Gregory, Len Cardillo, Benjamin R. Bunes, Sawyer D. Campbell, Pingjuan L. Werner, Douglas H. Werner
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Access
• Subjects: Ammonia; frequency selective surface; low power; remote sensing; tunable; varactor
• Online Access: https://ieeexplore.ieee.org/document/9393901/

In this interdisciplinary work, a low-power varactor-tunable frequency selective surface is presented for use with a multiplexed remote sensor system. Combined with a low power sensor and control system, voltage biasing of the proposed frequency selective surface panel can be used to modulate the center frequency of a reflection peak, which in turn may be detected by remote interrogation through a radar system. The control board and frequency selective surface were found to draw only <inline-formula> <tex-math notation="LaTeX">$200~\mu \text{A}$ </tex-math></inline-formula> of current during typical operation from two 3V CR2032 button batteries, enabling continuous operation for weeks at a time (even longer if operated in wake-up mode) when used in conjunction with a suitably low power sensor. Centered at 3 GHz, the backscatter peak can be modulated across a range of 200 MHz, and the combined system was shown to successfully differentiate between various concentrations of ammonia under test conditions.