CPW Grounded calculators

Hello

I've a question about, CPW calculators, I've searched foe some softwares and siteweb that provide calculators of CPW impedance but I ve found that results are not simulars and some of them give the possibility to choose the frequency and others not

Does someone know the causes of this, are there different methods of calculation? does the impedance of CPW depend on frequency? I ve tested to change frequency and I've noticed that not or (alittle) change the result


many thanks

CPW has a zero cut-off frequency, which means the structure theoretically doesn't depends by frequency.
But experimentally was found that this is valid only up to several GHz, point where the Transverse Electromagnetic field (TEM) became Transverse Electric (TE).