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

• Published in: IEEE access 2021, Vol.9, p.58478-58486
• Main Authors: Jenkins, Ronald P., Gregory, Micah D., Cardillo, Len, Bunes, Benjamin R., Campbell, Sawyer D., Werner, Pingjuan L., Werner, Douglas H.
• Format: Article
• Language: English
• Subjects: Ammonia; Backscattering; Chemicals; Control systems; frequency selective surface; Frequency selective surfaces; Interrogation; low power; Multiplexing; Power management; Radar equipment; Reflection; Remote sensing; Remote sensors; Sensors; tunable; Tuning; varactor; Varactors
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2021.3070715

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 200~\mu \text{A} 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.