On the fundamental Q-bandwidth relations for antennas

A procedure for extracting the unloaded Q of antennas was presented. The technique accurately predicts the asymmetric response in the reflection coefficient of canonical antenna problems. Portions of the verifications using different commercial solvers were listed in this short paper. The proposed technique is extremely useful when designing different classes of antennas. Its extension to multi-pole models provides a promising systematic method for the design of multiband/wideband antennas. It should be emphasized that the analysis is not limited to naturally resonant structures, and can be extended to study Q and BW of electrically small antennas.