I'm looking for the equation which relates Vgs1, Vth1, Vgs2, and Vth2 to Id.
For a single gate MOSFET, this is:
\[{I}_{D}={I}_{DSS} \cdot \left[ \left( {V}_{GS} - {V}_{TH}\right) \cdot {V}_{DS} - \frac{ {{V}_{DS}}^{2} }{2}\right]\]
or the approximation
\[{I}_{D}={I}_{DSS} \cdot \left( {V}_{GS} - {V}_{TH} \right) \cdot {V}_{DS}\]
where
\[{I}_{DSS}={k}_{n}\left(\frac{W}{L}\right)\]
I haven't found much about how to apply this to dual gate MOSFETs, however.
Re: Looking for Dual Gate MOSFET Vgs vs. Id equations
For anyone who was curious about the answer to this question, I went to a professor at my university and asked him. Turns out that the answer is much simpler than I expected. A dual gate mosfet is modeled as two MOS transistors, connected source-to-drain.
In effect, a dual gate mosfet is a single-element cascode amplifier.