一种基于对称PCB结构的GaN器件高带宽电流检测方法

A high bandwidth current measurement method for GaN devices based on symmetrical PCB structure

针对氮化镓器件高频开关动作,开关电流难以准确测量的难题,提出了一种基于对称印制电路板结构的高带宽电流检测方法。该方法利用电流分流器原理检测氮化镓器件电流,基于磁感应原理对印制电路板进行了优化设计,通过控制电流在印制电路板上的流通路径,使分流电阻的寄生电感部分被抵消,并配合适当的补偿网络和前置放大器,实现在宽频带测量范围内具有平整的幅频特性。同时,本文提出的电流检测方法所需印制电路板结构紧凑,较商用同轴分流器易于安装。搭建了一套适用于氮化镓器件的宽频带双脉冲测试电路,将本文提出的电流检测方法与商用同轴分流器检测方法进行了对比测试。测试结果验证了所提出电流检测方法的有效性和准确性。

For the GaN device high-frequency switching action,the current is difficult to be measured accurately,and a high-bandwidth current detection method based on symmetric PCB structure is proposed.The method uses the current shunt principle to detect GaN device current,optimizes the design of the printed circuit board based on the magnetic induction principle,makes the parasitic inductance of the shunt resistor partially canceled by controlling the current flow path on the PCB board,and cooperates with appropriate compensation networks and preamplifiers to achieve a flat amplitude and frequency characteristic in the wide bandwidth measurement range.At the same time,the proposed current detection method requires a compact PCB board,which is easier to install than the commercial coaxial shunt.A wide-band double-pulse test circuit for GaN devices is built,and the current detection method proposed in this paper is compared with the commercial coaxial shunt detection method.The test results verify the effectiveness and accuracy of the proposed current detection method.