Amarjit Singh Bhandal

Causality checking and enhancement of 3D electromagnetic simulation data

A causality checker is developed and used to validate and improve S-parameter data computed with a commercial 3D electromagnetic simulator. Improved data quality as shown by the causality checker is demonstrated to fix a flawed SerDes link simulation and an impedance extraction based on a TDR simulation. It is demonstrated that simple examination of the S-parameters cannot differentiate between good and bad data as shown by the causality checker. Furthermore, it is demonstrated that the causality checker can determine when frequency is under-sampled in the 3D electromagnetic extraction.

Improving high-speed SerDes performance using passive microwave filters along package traces

Lab measurement and simulation results are presented to show how passive capacitive microwave filters along flip-chip package traces can be used to overcome the capacitive discontinuity at the output port of SerDes transceivers to improve link performance. The technique is further developed to demonstrate its ability to shape the near-end eye pattern to improve its height and/or jitter at different data rates up to 17Gbps. The benefits of the technique for devices which deploy many 10s or 100s of SerDes links are highlighted.

Package design for high-speed SerDes

High-speed SerDes signals are significantly distorted by the time they leave the package. The distortion is caused by excess capacitive loading at points along the signal path, causing reflections. The reflections can be minimized through design modifications, added structures for compensation, filters, and characteristic impedance shifts.