An improved ultrasonic horn of the cosine type is studied.The frequency equation, formulae for calculating the performance parameters and the four-terminal network parameters are given.

• 摘要推导了改进的馀弦形超声变幅杆的频率方程、各参数的计算公式以及等效四端网络传输矩阵参量，并与其它类型的变幅杆进行比较。