i have attached a research paper. it shows one differential lc ring oscillator (fig 3.). i want to know how to vary tail current bcoz i want to show dependence of tail current on phase noise.i want to do this in mentor graphics da-ic tool.
But to see connections between different factors, I would tell you to try out Geogebra. It has built in spread sheet with complete support for imaginary numbers. Combined with functions like FitLine that calculate the probability line, it's a very useful tool. But you need to take time to get familiar with it.
Latest version (beta with more functions) is to be found here. No need for install, but you must have java installed.
what you mean i want to know how to vary tail current? you can sweep the width of transistor to vary the current(Id is proportional to width) so you can investigate phase noise