High-Gain Antipodal Vivaldi Antenna With Pseudoelement and Notched Tapered Slot Operating at (2.5 to 57) GHz

Novel methods of improving directivity and decreasing sidelobe radiation via the addition of an elliptical pseudoelement and irregularly spaced notches in the tapered slot antenna are presented in this paper. This antenna has been shown to be functional over the C, X, <inline-formula> <tex-math notation="LaTeX">$\text{K}_{\mathrm {u}}$ </tex-math></inline-formula>, K, <inline-formula> <tex-math notation="LaTeX">$\text{K}_{\mathrm {a}}$ </tex-math></inline-formula>, and portions of the <inline-formula> <tex-math notation="LaTeX">$S$ </tex-math></inline-formula>- and <inline-formula> <tex-math notation="LaTeX">$V$ </tex-math></inline-formula>-bands covering (2.5 to 57) GHz (22.8:1 bandwidth, defined where VSWR < 3). Minimum and maximum realized gains of 4 and 16 dB were achieved at 2.7 GHz and 29.8 GHz, respectively. The antenna offers directive radiation patterns with a half-power beamwidth under 40° for frequencies above 6 GHz and under 30° for frequencies above 32 GHz. As compared with other Vivaldi antennas reported in the past, the proposed design offers a larger bandwidth while providing higher peak gain and average gain. Good agreement was observed between simulation and measurements.