Time-Domain Analysis and Design of GCPW Vertical Transition Using Eccentric Via-hole in Multilayer PCB

In this paper, a grounded coplanar waveguide (GCPW) vertical transition using eccentric via-hole is proposed and its time-domain pulse transmission performance is analyzed. By offsetting the antipad, a 90 degrees eccentric transition structure is fabricated on multilayer printed circuit board (PCB). To characterize transmission performance of proposed transition in digital system, the normalized Euclid distance (NED), a comprehensive parameter used in time-domain analysis, is applied to evaluate the trapezoidal pulse performance of the transition. Results indicate that eccentric via-hole has better field transition thus better pulse transmission performance comparing to conventional concentric structure, presenting reflection coefficient almost less than -10 dB up to 20 GHz, and NED is equal to 0.0532. Time-domain analysis using NED in digital signal is viable, and measured results show good pulse transmission performance of the design.