Automated 3D discontinuity optimization with speed sensitivity for high-speed Serdes channels

With the data rate increasing to 112 Gb/s, optimization of differential vias becomes critical for high-speed designs, as discontinuity of differential vias can severely impact signal qualities. Achieving a good differential via design for higher frequencies is becoming more and more challenging. In this paper, we present an unconventional way to optimize the differential vias, which is using different antipad sizes for input/output antipads and middle anipads. We then perform sweeping with different parameters and analyze the S-parameters by examining their impact on TDR, TDT, Group Delay, and eye diagrams. Our Python coding helps identify the optimization trend and make the complete sweeping fully automated with designated signal speed as a sensitive target.