微波频段铁电体的铁电性测量系统

设计了一套在微波频段下测量铁电体块材铁电性的测量系统。该系统采用微带线结构，测量时将两端具有电 极的铁电体块材放置在断开的微带线中间。可以在铁电体两端施加高达2000V 的直流电压，来测量铁电体的介电常 数随偏压的变化规律。设计了直流偏置电路和高压保护电路，以保证矢量网络分析仪的安全。用TRL 法进行校准， 得到待测材料的参数。编写了自动测量软件，采用VC++通过网线从矢量网络分析仪中读取测量数据，采用MATLAB 进行数据处理，得到微波频段下铁电体铁电性的测量结果。

A Paraelectricity Measurement System of Ferroelectrics at Microwave Frequencies

A measurement system that can obtain the paraelectric property of bulk ferroelectrics at microwave frequencies is presented. In the measurement, a rectangular-cuboid ferroelectrics with a pair of electrodes at opposite sides which represents a lumped capacitor is placed between a gap of a microstrip line. The paraelectric property can be measured under high DC bias up to 2000V. Blocking capacitors and a-quarter-wavelength stub lines are used to make sure that the vector network analyzer is double safe in the presence of high voltage. Thru-Reflect-Line (TRL) calibration method is used to de-embed the ferroelectric capacitor from blocking circuits and DC bias networks. To design the automatic measurement software, VC++ is used to acquire the data from vector network analyzer, and MATLAB is used to analyze the data to get the paraelectric property.