\small K_U = \cfrac { s^2 \, \cfrac {1} { 1 + \cfrac {R_0} {R_2 || R_1} } } { \cfrac {1} {C_1 \, C_2 \left[ \, R_1 \, R_2 + R_0 \left( R_1 + R_2 \right) \, \right]} + s \left( \cfrac {1} {C_1 \left( R_2 || R_0 + R_1 \right)} + \cfrac {1} {C_2 \left( R_2 || R_1 + R_0 \right)} \right) + s^2 }