A design method of high-compatibility horn for broad-bandwidth transducer

Broad-bandwidth transducers are one of the main areas of focus for the development of power ultrasonic systems, which address the issues that the contactless transformer system cannot track transducer frequency and narrowband transducers are not compatible with different tools. This paper aims to investigate the potential capabilities of broad-bandwidth transducers in terms of compatibility with different horns and to propose a design method for highly compatible tools. The frequency equation of horn is nondimensionalized to calculate relative frequency errors δ. The effects of shape, dimensionless size, and order number on δ are investigated based on the equation. A compatibility range is proposed, and the relationship between it and the required relative bandwidth of the transducer is investigated. Various horns were designed, and the corresponding simulations, impedance measurements, and resonance experiments were conducted to explore the effects of these factors on δ, amplitude, and the quality factor Q. These experiments also verified the feasibility of using a broad-bandwidth transducer that is compatible with different tools. Finally, the application scenarios of the three horns are summarized based on a comparison of their matching ability, amplitude, operational stability, and compatibility range.