#### GGAPBE96

##### Member level 2

**resistance equation**

Many references say negative resistance of colpitts oscillator can describe the following equation.

-R = -gm/ ω^2/C1/C2 (gm :: trans conductance of FET)

However,negative resistance is also proportional to the ratio "C1/C2".

Does anyone tell me how to develop the expression for the exact negative resistance?

Thanks,