以主动式毫米波全息成像的应用为背景,中国科学院上海微系统与信息技术研究所研制的异质结AlGaAs/GaAs PIN二极管毫米波开关为安检成像领域的关键核心器件,为此提出一种基于高、低阻抗变换线的补偿结构以优化高频处的匹配程度。设计合适的毫米波倍频链路、低插入损耗的带通滤波器以及低插入损耗和高隔离度的开关通道阵列,实现一款满足系统要求的输出功率和一致性且谐波抑制良好的发射前端。结果表明,在28~34 GHz频段内,各通道的输出功率大于10 dBm,谐波抑制度大于22 dBc,通道间的隔离度大于23 dB,通道间的差异小于2 dB,满足主动成像发射端的要求。集成相应天线阵列和接收前端后进行成像实验,可以得到分辨率为0.5 cm的毫米波成像。

With the application of active millimeter-wave holographic imaging as the background, the heterojunction AlGaAs/GaAs PIN diode millimeter-wave switch developed by the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences is a key core device in security imaging field. A compensation structure based on high and low impedance transform lines is proposed to optimize the matching degree at high frequencies. A millimeter-wave frequency doubling link, a low-insertion-loss bandpass filter, and a low insertion loss and high isolation switch channel array are designed to achieve a transmission front end that meets the requirements of the system with output power and consistency and good harmonic suppression. The results reveal that in the 28--34 GHz frequency band, the output power of each channel is more than 10 dBm, the harmonic suppression is more than 22 dBc, the channel isolation between channels is more than 23 dB, and the channel difference is less than 2 dB, all of which meet the requirements of active imaging transmitter. The imaging experiment can be performed after integrating the appropriate antenna array and the receiving front end, and the millimeter-wave imaging with a resolution of 0.5 cm can be acquired.