On Q-factor Bounds for Lossy Embedded Antennas in Electrically Small Devices
Résumé
In this paper we investigate a method to determine the best available bandwidth for small embedded antennas. The available bandwidth depend both on the size and the position within a device, but also on the ohmic losses in the structure. Here we show a non-convex optimization problem, utilizing stored energies, and phrased as a current optimization problem we can determine theavailable bandwidth in a given region for a range of surface resistances. We illustrate the method by comparing the results with embedded antennas in a small IoT terminal. We show that an optimized embedded come rather close to the bounds.