测试环境对卫星转发器幅频特性影响分析和修正方法

Effect of Test Circumstances Analysis on Amplitude-frequency Characteristics for Satellite Transponder and Its Modification Methods

卫星通信转发器中使用的部分滤波器是波导滤波器。波导滤波器的中心频率在不同测试环境下会发生变化,若测试时不进行修正,将影响转发器幅频特性的测试结果,不能准确反映卫星转发器真实特性。本文首先描述了卫星通信转发器的幅频特性测试原理;然后给出了在常温常压测试环境下转发器测试中心频率的偏移系数计算公式,以卫星C/C转发器为研究对象,讨论卫星转发器的中心频率正确选择的方法,分析了不同测试环境对测试结果的影响;最后提出了对未考虑测试环境影响的测试数据的修正方法。

Some filters used in satellite transponder are waveguide filters.The central frequency of waveguide filter could vary in different circumstance.If the test frequency is not modified according to the variation of test circumstances,the test result of amplitude-frequency characteristics of transponder must be affected,and it cannot character the real transponder.The paper discribes first the test method of amptitude-frequency characteristics,then the formulae of the offset coefficient are derived for central frequency of communication satellite in normal environment.The test case of a C/C transponder for communication satellite is taken.The principle how to choose the transponder central frequency is proposed.The effect on test results is analyzed in different circumstances.A modification method for test neglecting the effect of test circumstance is provided in the paper.