AnsweredAssumed Answered

Tunnel Diode Models

Question asked by daniels on Jun 8, 2015
Latest reply on Sep 14, 2020 by navelorange93
Recently, I decided to try to create an ADS model of the trigger input circuits in the old HP 1425A timebases, the reason being that I still use one, and I was hoping to figure out how to improve the bandwidth of the system slightly, and perhaps also to adapt it to modern replacement components, since there is no source of replacements for the diodes used in the inputs.
Almost immediately, upon starting in on this, I realized that there appears to be no general purpose tunnel diode model in ADS. needless to say, I wasn't very surprised, this seems to be the norm for circuit simulators. I was able to track down a document from Aeroflex describing how to model them in spice, so I should be able to do that and import the files, but all of this made me wonder if I were going about this in the right way. 

I'm fairly new to ADS, so as yet I have very little experience creating models for individual components, but modeling things in spice and then importing them seems to be a fairly inelegant solution to the problem, and so I suspect that there must be an easier and faster way to do this. My question, thus, is whether there is a simple method to model negative resistance devices, like tunnel diodes, directly in ADS?