Miniaturized Ultra-Wideband Vivaldi Antenna Using Asymmetric Matching

In this paper, a miniaturized all-metal ultra-wideband Vivaldi antenna with an asymmetric matching structure is proposed. The Vivaldi antenna is designed for applications that require high structural strength and heat resistance. The curved slot and the feeding coaxial line of the Vivaldi antenna are connected using an asymmetric matching structure to achieve an extended operating bandwidth. Bessel functions are employed to optimize the gain and radiation pattern of the antenna. The antenna board thickness is segmented and optimized for impedance matching in the high-frequency range, while the addition of rectangular slots optimizes impedance matching in the low-frequency range. Simulation results demonstrate that the antenna achieves an impedance bandwidth of 22:1, with S11 parameters below −10dB within the frequency range of 3-69 GHz. Additionally, despite its asymmetric design, the antenna exhibits good symmetry in the radiation patterns, with no significant splits observed in the main lobes across the frequency range of 3-69 GHz.