Learning Forum

[HAOYU LIU]

For transient to test the bandwidth, the recombination parameters will not affect too much. But when using the ssac to test the bandwidth, the recombinations count a lot, escpecially the surface recombination velocity for Ge (absorption layer) and Si (drift layer). For some situation, the bandwidth will decrease as the bias voltage increase and the UTC-PD bandwidth will decrease when using the graded doping in the absorption layer, it violate the principle. The bandwidth should increase as the bias voltage increases for a range. I want to know how to set the appropriate parameters in the ssac, the parameters in the example of vertical PD are not suitable for my model.

[Khashayar Ghaffari]

Hi,

Please first refer to the detailed discussion regarding ssac vs transient simulation here (in Appendix). Specifically the correct choice depends whether you expect linear responde from the photodetector. More info is shared on the article.