I'm looking for a circuit that performs a harmonic oscillation while its resonance frequency can be controlled with a microcontroller (preferably via an analog signal). The circuit has to drive a set of ultrasonic transducers with a maximum power of 100 W at ~ 50 V and a maximum frequency of 100 kHz.
Till now I'm using a h-bridge circuit for my low-power setup (using the 0D24K2 transducers) which dissipates most of the power by (dis-)charging the transducers' capacitance. I can't find any datasheet, but it might be similar to When I now increase power and frequency, power dissipation will increase as well. Another disadvantage is that driving the transducers with a square wave generates unwanted higher harmonics, but I'd like to have a signal with a pure spectrum.
Some solutions that came to my mind are using:
a LC resonant circuit, but right now I'm unsure how to control its frequency with a microcontroller.
an oscillating circuit with operational amplifiers. I guess it might be difficult to generate the needed power and frequency at acceptable cost.