The vibration characteristics of three common shape functional ultrasonic transformers with reactive load are analyzed by numerical calculation. The result shows that the resonance frequency elevates with the increase of capacitive load, while it reduces with the increase of inductive load. The amplitude magnification coefficient decreases with the increase of capacitive load, while it increases at first and then decreases with the increase of inductive load. The resonance frequency and amplitude magnification coefficient of conical transformers are less influenced by load, but catenary and exponent transformers have their advantage on amplitude magnification coefficient on little load condition.

ultrasonic transformer; resonance frequency; amplitude magnification coefficient