A capacitor for use with RF signals of an operating frequency has a parallel plate configuration including a bottom electrode, a top electrode, and a dielectric layer disposed between the bottom and top electrodes, and an additional mass layer disposed on top of the top electrode. The parallel plate configuration is capable of receiving a DC voltage bias that affects the capacitance value of the parallel plate configuration, and exhibits a standing wave resonance frequency at the operating frequency. The mass layer has a density and a thickness selected to dampen the magnitude of the resonance of the parallel plate configuration at the standing wave resonance frequency and shift the standing wave resonance frequency away from the operating frequency.