Ultra-Wideband and Low-Profile Design of Tightly Coupled Dipole Antenna

In this paper, an ultra-wideband tightly coupled dipole antenna (TCDA) unit operating at 2–18 GHz (9:1) is designed. The cell has a pass size of
$5\ \text{mm}\times 5$
mm and a profile height of
$0.084\lambda_{\mathrm{L}} ( >\lambda_{\mathrm{L}}$
is a low-frequency wavelength). The antenna unit eliminates short-circuit resonance points by loading a resistive frequency-selective surface (RFSS), and common mode resonance elimination is achieved by shorting the columns and lowering the dielectric constant. The antenna unit can realize an E-plane sweep angle of
$\pm 45^{\circ}$
and an Active VSWR of less than 3. At Active VSWR less than 3.5, the H-plane sweep angle
$\pm 45^{\circ}$
.