A Low Profile and Extremely Wide-Band Tightly Coupled Array with Special Balun Structure

An extremely wide-band tightly coupled dipole antenna array(TCDA) is presented. A novel balun is developed with a spoof surface plasmon polariton (SSPP) structure and a RC resonant circuits to achieve impedance matching and a conversion from unbalanced dipole feeding to balanced feeding. According to the simulation, the proposed TCDA demonstrates a remarkable 60:1 bandwidth (0.08GHz-4.83GHz) with VSWR<2.5. The overall array thickness is
$0.03{{{\lambda }}}_{\text{low}}$
(where
${{{\lambda }}}_{\text{low}}$
is the wavelength at the lowest frequency of operation, 80 MHz). The final array design consists of 12 dipole unit cells arranged in a one-dimensional configuration.