A Miniaturized UWB TEM Horn Antenna Design

In this paper, an UWB TEM horn antenna in the form of a combined oscillator is designed. On the basis of the TEM horn antenna with exponential changes in both impedance and board spacing, the end of the horn antenna is bent and extended in reverse, and then connected with the metal board loaded with S-shaped structure at the back end to form a closed loop, thereby improving the matching performance at low frequencies. In addition, the matching strip is loaded between the TEM horn surface and the parallel boards, which further optimizes the matching performance at low frequencies, thereby realizing the miniaturization of the antenna. The size of the antenna is about
$218.41\ \text{mm}\ (\text{opening})\times 100\ \text{mm}\ (\text{axial})\times 97.45\ \text{mm}$
(width), and the simulation results show that the VSWR in 0.38-10 GHz is less than 2 and the average gain in the band is about 9 dBi.