How does one work out the value of capacitance needed for a capacitor in a simple circuit (a resistor and a capacitor in series)? Some engineers at my work are testing something with the circuit, and when I asked some questions, they said learning how to work out the values of the capacitor would be a good learning exercise. "The capacitance is 1/jw(omega)C", but I'm not sure what else I need to know (I have Zsource and Zload data), or how to go about solving.

Question

anonymous · Answer

capacitance depends on the geometry of the plates by which it is made of, the formula is 
$$C = \epsilon A/d$$ where A is the area of one plate and d is the separation between them .
when the capacitance is known then the reactance it offers can be calculated by the above mentioned formula where $$\omega $$ = the frequency of supply voltage .
by determining how much impedance is to be required in the circuit with a given frequency one can calculate the required capacitance using the same formulas