Embodiments of impedance matching networks are provided herein. In some embodiments, an impedance matching network may include a coaxial resonator having an inner and an outer conductor. A tuning capacitor may be provided for variably controlling a resonance frequency of the coaxial resonator. The tuning capacitor may be formed by a first tuning electrode and a second tuning electrode and an intervening dielectric, wherein the first tuning electrode is formed by a portion of the inner conductor. A load capacitor may be provided for variably coupling energy from the inner conductor to a load. The load capacitor may be formed by the inner conductor, an adjustable load electrode, and an intervening dielectric.