Miniaturized Time-Domain Antenna With Improved Low-Frequency Radiation Performance

A miniaturized endfire antenna with improved low-frequency radiation performance (RP) is proposed for time-domain applications. Through a novel resistive loading (RL) method, the proposed time-domain antenna (TDA) has a compact size of 0.176 λ
_L
(
L
) × 0.156λ
_L
(
W
), and improved low-frequency RP. Note that, this improvement does not mean the improvement of radiation efficiency, but means the enhancement of the radiation in forward and the reduction of the radiation in backward. Furthermore, the size of the proposed TDA is reduced by 78% as compared with the traditional antipodal Vivaldi antenna. In order to provide a certain reference for the design of endfire TDAs, the mechanism of the novel RL technique is explored according to the design. Measured results show that the bandwidth of the proposed TDA is 0.168–3 GHz (179%). Due to the compact size and good time-domain performance, the proposed TDA can be a good candidate for time-domain applications such as ground penetrating radar, through-wall radar, and high-power pulsed source. Meanwhile, the novel RL technique can be a prior solution for the miniaturization and low-frequency RP improvement for endfire TDAs.