Periodic spherical loop antenna

In this paper a volumetric approach to miniaturizing a 300 MHz loop antenna is presented. Leveraging the benefits of additive manufacturing allows for the antenna to be meandered in a spherical pattern resulting in higher levels of miniaturization while maintaining efficiency. A parametric study provides a design guideline comparing electrical size of the radian sphere (ka) with input impedance. Fabrication is achieved using a combination of additive manufacturing and traditional methods. Measured results demonstrate a ka of 0.43 with a quality factor 1.76 times the Chu limit.