A BOR-SPR Antenna Operating from 2 GHz to 18 GHz

In this paper, an ultra-wideband BOR-SPR antenna with an antenna height of $0.07 \lambda_{L}\left(\lambda_{L}\right.$: free-space wavelength at 2 GHz) is proposed. It is found that a VSWR of less than 3 is obtained across a frequency range of $2-18 \mathrm{GHz}$ (a fractional bandwidth of $160 \%$). The proposed antenna radiates a conical beam. The antenna gain is more than $-1 \mathbf{d B i}$.