cascode amplifier of unequal width of transistors

hi,

I am deriving equations for optimizing cascode amplifier. Usually, when the same dimensions (W1/L1 =W2/L2) of transistors, the same current will flow. But if I am changing the width of cascode transistor, the current will vary. How to find the current of main transistor and cascode transistor analytically. Please give me the equations or any example .