Photoacoustic Substitution Method for Calibrating Subterahertz Attenuation in Free Space
Photoacoustic Substitution Method for Calibrating Subterahertz Attenuation in Free Space
复制标题
自由空间中亚赫兹衰减的光声替代法校准
DOI：
10.1109/tim.2021.3060577
复制
发表时间：
2021
影响因子：
5.6
通讯作者：
Hitoshi Iida and Moto Kinoshita
中科院分区：
文献类型：
--
作者：
塚本耕助;須田隆夫;Hitoshi Iida and Moto Kinoshita
使用自由空间光束光声 (PA) 探测器开发了太赫兹 (THz) 衰减校准系统。该系统基于PA探测器的原理，用音频（AF）衰减代替射频（RF）衰减来测量太赫兹衰减。使用感应分压器（IVD）作为参考标准直接校准 1 kHz 下的 AF 衰减。针对 0.11 THz 频率下高达 20 dB 的金属化薄膜衰减器进行了校准演示。带有波纹喇叭天线的耿氏振荡器用作源，其辐射光束使用离轴抛物面镜进行准直。还详细讨论了不确定性的来源，发现扩展的不确定性为 0.40-0.46 dB (k = 2)。
A terahertz (THz) attenuation calibration system is developed using a photoacoustic (PA) detector for free-space beams. Based on the principle of the PA detector, the system measures the THz attenuation by substituting radio frequency (RF) attenuation with audio frequency (AF) attenuation. The AF attenuation at 1 kHz is directly calibrated using an inductive voltage divider (IVD) as the reference standard. The calibration is demonstrated for metalized film attenuators up to 20 dB at 0.11 THz. A Gunn oscillator with a corrugated horn antenna is used as the source, and its radiated beam is collimated using an off-axis parabolic mirror. Sources of uncertainties are also discussed in detail, and the expanded uncertainty is found to be 0.40-0.46 dB (k = 2).