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Multi-turn, printed surface coil inductance, and Q optimization.

A Raad·S Kan
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Abstract

Wheeler's empirical inductance formula for a multi-turn, close-wound flat coil shows that the maximum inductance for a given length of wire occurs when the outer to inner radius ratios is equal to 15/7. A similar expression is proposed for a flat, printed spiral for surface coil antenna design by modifying one of the coefficients in Wheeler's formula. Measured inductance is in good agreement with this new formula and the optimum radius ratio for maximum inductance or Q is now of the order of 9/5.

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A Raad, S Kan. 1993. Multi-turn, printed surface coil inductance, and Q optimization.. https://doi.org/10.1002/mrm.1910290318

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