Design of TCDA Avoiding Half-wavelength Limitation Using PC

Low-profile array antennas are important in many defense and commercial communication systems. Although tightly coupled dipole arrays (TCDAs) have several advantages, their bandwidth is limited by their ground plane. The use of resistive frequency-selective surfaces to overcome this limitation generates ohmic losses which then deteriorate the radiation efficiency of the array antenna. In this paper, we propose a 4x4 TCDA with no ohmic loss. The proposed array employs a polarization convertor to overcome bandwidth limitation when antenna height is half the wavelength ($\lambda$). The impedance bandwidth for VSWR $\lt 3$ covers 0.43–8.06 GHz to broadside radiation (18.7:1), and antenna height is 0.07$\lambda_{{\mathrm {low}}}$ at the lowest operating frequency.