A coplanar capacitor that incorporates teachings of the subject disclosure may include: a substrate; a voltage-tunable dielectric layer over the substrate; a plurality of bias lines over the voltage-tunable dielectric layer (wherein the bias lines are covered by an inter-level dielectric); a plurality of sidewall spacers (wherein each of the sidewall spacers is located adjacent one of the bias lines and each of the sidewall spacers spans between a respective portion of the voltage-tunable dielectric layer and a respective portion of the inter-level dielectric); and an electrode over the inter-level dielectric, and over portions of the voltage-tunable dielectric layer that are not covered by the plurality of bias lines and that are not covered by the sidewall spacers, wherein a plurality of gaps are disposed in the electrode. Other embodiments are disclosed.