摘要
在多频通信环境中 ,如船载通信系统、蜂窝式移动通信基站和卫星地面接收站 ,无源互调产物一旦落入接收通带 ,就可造成严重的无线电干扰 ,它已成为此类通信系统的重要性能指标之一。本文介绍了无源互调问题的基本概念、推导了无源互调幅度的数学表示式、描述了无源互调测量的基本类型并给出了一个典型的无源互调测量系统 ,利用一个简化的无源互调测量系统对五阶无源互调功率电平进行了测量 ,并与理论值进行了比较 ,初步验证了测量系统的有效性和正确性。
In multifrequency comounications environments,such as ship-carried communication systems,cellular mobile radio communication base stations and satellite earth stations,passive intermodulation (PIM)product can cause serious radio interference once it falls into the receiving frequency band.It has been regarded as one of the performance parameters of considerable importance of communication systems.The basic concept of PIM problem is introduced.An expression of PIM amplitudes is derived.The basic types of the measurement systems of PIM products are described and a typical PIM measurement setup is given.PIM power measurement is carried out with a simplified setup system.The measurement data are compared with theoretical values,verifying the correctness and validity of the system.
