This paper analyzes the reasons of inaccurate PCB impedance simulation of the traditional simulator and introduces a novel and cost-effective method for accurate PCB impedance simulation of any specific stack-ups. The new method doesn't need to extract material properties from prototype boards or empirical modified DK from PCB Fabs. The test results show the new method & tool have better precision simulation ability with deviation less than 2.5%, compared with traditional simulation tool. It can meet the requirement of less than 5% tolerance impedance to match the high speed & high frequency PCB design, and consequently leads to a more cost-saving and time-saving method to rapidly occupy the market.
Impedance control plays an important role for both PCB designer and PCB Fabs. The accuracy of impedance simulation is the key factor to meet the spec and control cost. Nevertheless, through a large quantity of research papers  and product data, which I obtained from some PCB Fabs, it is indicated that there is a big deviation on PCB impedance simulation, often off by >5%, and the most off range:5%~15%, even more than 15%.