module: vco_noise
parameters: double noise_at_foff, double foff, double kv
inputs: 
outputs:  double out
static_variables: double noise_var
classes: Rand randg("gauss");
init: 
noise_var = foff*foff/(kv*kv)*pow(10.0,noise_at_foff/10.0);
code:
out = sqrt(noise_var/Ts)*randg.inp();
