基于AFR夹具去嵌研究

Research on Fixture Removal Based on AFR

射频低噪放的封装工艺向表贴、小型化持续发展,测试此类低噪放必然需要连接微带测试夹具。连接此类测试夹具进行测试令测试模型更加复杂,对测试和建模的精度都提出了更高的要求。因此对射频低噪放进行精确测试得到其散射参量(S参数),并准确建立测试模型是提高电路设计成功率和保证产品可靠性的重要环节。常规SOLT校准方法局限于同轴连接方式,无法校准夹具的微带部分,对于含微带线的夹具校准效果较差。本文利用自动夹具移除(AFR)算法,通过计算多项误差模型得出夹具的S参数,将夹具S参数导入矢量网络分析仪对测试夹具引入的误差进行修正,极大优化了测试结果。

The packaging process of RF low noise amplifier developed rapidly to surface-mounting and tiny,it was necessary to use test fixtures with microstrip lines to test such chips.Using such test fixtures with microstrip lines made the test model more complex,and puts forward higher requirements for the accuracy of testing and modeling.Therefore,it was an important link to improve the success rate of circuit design and ensure the reliability of the product by accurately testing the RF LNA to obtain its scattering parameters(S-parameters)and establishing the test model accurately.The conventional SOLT calibration method was limited to the coaxial connection,which could not calibrate the microstrip part of the fixtures,and the calibration effect was poor for the fixtures containing the microstrip lines.This article uses the Automatic Fixture Removal(AFR)algorithm to obtain the S-parameters of the fixture by calculating a multinomial error model.The S-parameters of the fixtures were imported into the vector network analyzer to correct the errors introduced by the test fixtures,which greatly optimized the test results.