Design of a Triple-Mode Wideband Antenna Using Theory of Characteristic Modes

The theory of characteristic modes (TCM)is utilized to design a triple-mode wideband antenna in this paper. The antenna consists of two dipole resonators and one loop resonator. First of all, a full characteristic mode analysis of the antenna structure was carried out. It was observed that the first three characteristic modes (CMs)of the antenna can be used to design a wideband antenna. Then, a proper feeding network was designed to excite those selected CMs. After optimizing the antenna's geometric parameters, a wide impedance bandwidth of 56.9% with | S
₁₁
|<;-10 dB can be obtained.