Optimization of the transition from connector to PCB board

Abstract

A transition from vertically launched coaxial connector to routed trace on board is simulated and optimized to achieve very small reflections for precise TRL calibration. The mismatch of the discontinuities in the transition was reduced by controlling the via-impedance, introducing capacitive via-pads and applying diving boards. Each segment was optimized first, and then the whole cascaded structure was simulated to achieve the optimized smooth signal transition.