Derivation of the Self-resonant Equations of Small Antennas by Using EM Simulation Results

Electromagnetic simulation results are very useful for understanding principles of antenna performances. In this paper, derivation method of self-resonant structural equations of a meander line and a normal-mode helical antenna are shown. The self-resonant equation is given by the equality equation of capacitive and reactive reactance. The inductive reactance equation is derived from the magnetic field distributions. The capacitive reactance equation is derived based on the electrical near field distributions obtained by electromagnetic simulator (FEKO) results. Self-resonant structures by the resonant equations and simulations are compared and good agreements are ensured.