when we model a structure with capacitor?

Hi.
I have a dielectric antenna structure that I want to model it by a resonant circuit.
I know how model it's resistor.But I don't know where and how,model a capacitance and inductor for it.
in general,when model a structure with capacitance and inductor?
in monopole wire antenna,we use from a parasitic capacitor between ground plane and top side of monopole.
in a monopole dielectric antenna,do I need this parasitic capasitor?also,how model a inductor for it?
thanks