N-Internal Port Design for Wide Band Electrically Small Antennas With Application for UHF Band

Component-loaded antennas are treated as antennas with internal ports. The proposed model explains, through simple numerical simulations and an optimization algorithm, the behavior of these antennas over a wide band. Two examples are studied; dipole-based antennas loaded with one internal port and two internal ports. Based on the proposed analysis, a UHF (0.47 GHz-0.86 GHz) antenna is designed and measured. It has 2 cm × 5 cm area, less than -6 dB reflection coefficient, omni-directional radiation pattern, and more than 90% efficiency. Measurements confirm the theoretical predictions.