High-resolution frequency-domain spectroscopy(FDS) is set up using a coherent and continuous wave terahertz(THz) emitter and receiver.THz waves are generated and detected by two photomixers with two distributed feedback(DFB) lasers.Atmospheric water vapor with different relative humidity is systematically investigated by the FDS.A high-frequency resolution of ~14 MHz is obtained with the help of Hilbert transformation, leading to a well resolved and distinct transmittance characterization of water vapor.Compared with conventional THz time-domain spectroscopy, the high-resolution continuous wave THz spectrometer is one of the most practical systems in gas-phase molecular sensing, identification, and monitoring.
对W波段带状注五间隙耦合腔的高频结构进行了设计与分析,以一个五间隙耦合腔作为输入腔,一个五间隙耦合腔作为输出腔,构成了W波段SBEIK的注波互作用系统,利用CST粒子工作室对整个注波互作用系统进行了三维计算模拟,并用Magic 3D对注波互作用计算进行了验证,结果表明两种PIC软件的计算结果基本一致.该SBEIK在电子注电压为75 k V、电流为4 A条件下,仅用两个腔体在W波段实现了高于24 d B的增益,为下一步高增益、高效率、小型化、紧凑型SBEIK的设计奠定了坚实的基础.
