Nineth-Order Butterworth Filter Function

** Circuit Description **
* input signal
Vin 1 0 AC 1V
* a cascade of biquads forming a 9th-order Butterworth Filter Function
* first biquad
R1 1 0 100Meg
E1 2 0 Laplace {V(1)} = { (6.773e+4)/(s+6.773e+4) }
* 2nd biquad
R2 2 0 100Meg
E2 3 0 Laplace {V(2)} = { (6.773e+4*6.773e+4)/(s*s+1.8794*6.773e4*s+6.773e4*6.773e4) }
* 3rd biquad
R3 3 0 100Meg
E3 4 0 Laplace {V(3)} = { (6.773e+4*6.773e+4)/(s*s+1.5321*6.773e4*s+6.773e4*6.773e4) }
* 4th biquad
R4 4 0 100Meg
E4 5 0 Laplace {V(4)} = { (6.773e+4*6.773e+4)/(s*s+1.0*6.773e4*s+6.773e4*6.773e4) }
* 5th biquad
R5 5 0 100Meg
E5 6 0 Laplace {V(5)} = { (6.773e+4*6.773e+4)/(s*s+0.3472*6.773e4*s+6.773e4*6.773e4) }
* output
Rout 6 0 1k
** Analysis Requests **
.AC LIN 100 1Hz 20kHz
** Output Requests **
.PLOT AC VdB(6) Vp(6)
.probe
.end