An Empirical Expression to Predict the Resonant Frequencies of Archimedean Spirals

作者：Hooker Jerris W^*; Ramaswamy Vijaykumar; Arora Rajendra K; Edison Arthur S; Withers Richard S; Nast Robert E; Brey William W

来源：IEEE Transactions on Microwave Theory and Techniques, 2015, 63(7): 2107-2114.

DOI：10.1109/TMTT.2015.2434814

• High-temperature superconducting (HTS) spiral resonators
• nuclear magnetic resonance (NMR)

This paper presents an empirical formula to accurately determine the frequencies of the fundamental and higher order resonances of an Archimedean spiral in a uniform dielectric medium in the absence of a ground plane. The formula is based on method-of-moments simulations, which have been experimentally validated. This empirical formula is widely applicable to a broad range of spirals from thin-ring to disk-shaped (ratio of inner to outer radii 0 to 1), with ten or more turns.