[Amps] Mica cap substitute \ alternative

[Peter Chadwick]

Rich said:
>Unlike barium-titanate dielectric (ceramic)  doorknob capacitors,  
whose current carrying ability increases from 5MHz to 30MHz, mica  
dielectric caps' current carrying ability decreases above 5MHz.<
Yes, but WHY? What's the mechanism that allows mica to be a perfectly good insulator in other application, way way up in frequency?
73
Peter G3RZP