Gifu University, Department of Electrical, Electronic and Computer Engineering, Gifu, 501-1193, Japan.
Osaka University, Department of Systems Innovation, Osaka, 560-8531, Japan.
Sci Rep. 2017 Aug 23;7(1):9203. doi: 10.1038/s41598-017-09802-0.
Near-field mapping has proven to be a powerful technique for characterizing and diagnosing antennas in the microwave frequency range. However, conventional measurement methods based on a network analyzer cannot be applied to on-chip antenna devices extensively studied for future wireless communication in the millimeter wave (mm-wave) (30-300 GHz) and terahertz (THz) wave (0.1-10 THz) frequency regions. Here, we present a new asynchronous mapping technique to investigate the spatial distribution of not only the amplitude but also the phase of the electric field generated by free-running, self-oscillating generators including CMOS oscillators, Gunn oscillators, resonant tunneling diodes, and quantum cascaded lasers. Using a photonic-electronic hybrid measurement system, a wide frequency coverage, minimal invasiveness of the field to be measured, and phase distribution measurements with a theoretically-limited sensitivity are simultaneously achieved. As a proof-of-concept experiment, we demonstrate the mapping of a mm-wave (77 GHz) generated by a free-running Gunn oscillator and antenna characterization based on near-to-far field transformation.
近场测绘已被证明是一种在微波频率范围内对天线进行特性描述和诊断的强大技术。然而，传统的基于网络分析仪的测量方法不能广泛应用于在毫米波及太赫兹波（30-300GHz 和 0.1-10THz 频率区域）范围内为未来无线通信而广泛研究的片上天线器件。在此，我们提出了一种新的异步测绘技术，不仅可以研究自由运行自激振荡器（包括 CMOS 振荡器、耿氏振荡器、共振隧穿二极管和量子级联激光器）产生的电场的幅度分布，还可以研究其相位分布。该技术采用光电混合测量系统，可实现宽频率覆盖、对被测场的最小干扰以及具有理论上有限灵敏度的相位分布测量。作为概念验证实验，我们演示了由自由运行的耿氏振荡器产生的毫米波（77GHz）的测绘以及基于近场远场变换的天线特性描述。
