A planar broadband antenna for UWB pulse transmission

In this paper, a modified Quasi-Yagi antenna with endfire radiation pattern is presented. A via connecting one arm of the driver dipole to the microstrip ground can be applied to replace the microstrip-to-CPS balun to achieve constant gain over a wider frequency range. The measured results demonstrate that an impedance bandwidth of 55% (S21<-10dB) and a relatively constant gain bandwidth of 70% (3dB to 5dB) can be obtained. Moreover, in terms of the constant group delay, the linear phase characteristic of this antenna can be verified. Additionally, a modulated Gaussian pulse is transmitted and received by using a pair of antennas to demonstrate the antenna's effectiveness for an UWB link.