Help me~
I'd like to make the circuit which capacitance are varying by the frequency.
I tried to make that by some capacitors and resistors but failed.
May not be the solution, just a throw to the sky.
1. Use a Frequency to Voltage Converter
2. Connect a VariCap (Varactor Diode) at the output side of Circuit 1
Do you really mean .93 PF? ,this is somewhat lower then the stray capacity of an inch or two of wire to earth. Inserting an inductor in series with a capacitor will change its apparent value right up to where the L and C resonate when their combined effect will lead to a very low value (series resonance).
Frank