Localized heating can be provided using fixed-frequency planar transmission line resonators arranged along a main-line, and tuning an electromagnetic input signal frequency applied to the main line to selectively address and energize one or more planar resonators for also addressing and energizing one or more correspondingly located active substrate transducer heat sources for depositing heat in an adjacent active substrate. More generally, adjusting input signal frequency to select one or more planar resonators arranged along a main line can be used to selectively address and energize an electromagnetic-to-heat, an electromagnetic-to-vibration, or other transducer to controllably direct energy toward a desired transducer load.