设计了一种小型介质双工器。它由高介电常数陶瓷介质同轴谐振器组成，其优点是体积小，成本低，各项性能指标优良，可用作４５０ＭＨｚ频段移动通信收发信机的天线双工器。本文同时用最小二乘边界余数法计算了介质同轴谐振器中心孔偏差问题，可对加工陶瓷介质谐振器工艺过程中的误差范围及各参数值的修正提供依据。 A small medium duplexer is designed. It consists of high dielectric constant ceramic dielectric coaxial resonator, its advantages are small size, low cost, excellent performance indicators, can be used as 450MHz band mobile communication transceiver antenna duplexer. In the meantime, the center hole deviation of dielectric coaxial resonator is calculated by the method of least square boundary remnant, which can provide the basis for the error range and the correction of each parameter value in the processing of ceramic dielectric resonator.