Lee Moon-Jeong, Lee Ha-Neul, Lee Ga-Eun, Han Seong-Tae, Yang Jong-Ryul
Department of Electronic Engineering, Yeungnam University, Gyeongsan 38541, Korea.
Electrophysics Research Center, Korea Electrotechnology Research Institute, Changwon 51543, Korea.
Sensors (Basel). 2022 Feb 23;22(5):1753. doi: 10.3390/s22051753.
A CMOS detector with a concurrent mode for high-quality images in the sub-terahertz region has been proposed. The detector improves output-signal coupling characteristics at the output node. A cross-coupling capacitor is added to isolate the DC bias between the drain and gate. The detector is designed to combine a 180° phase shift based on common source operation and an in-phase output signal based on the drain input. The circuit layout and phase shift occurring in the cross-coupled capacitor during phase coupling are verified using an EM simulation. The detector is fabricated using the TSMC 0.25-μm mixed-signal 1-poly 5-metal layer CMOS process, where the size, including the pad, is 1.13 mm × 0.74 mm. The detector IC comprises a folded dipole antenna, the proposed detector, a preamplifier, and a voltage buffer. Measurement results using a 200-GHz gyrotron source demonstrate that the proposed detector voltage responsivity is 14.13 MV/W with a noise-equivalent power of 34.42 pW/√Hz. The high detection performance helps resolve the 2-mm line width. The proposed detector exhibits a signal-to-noise ratio of 49 dB with regard to the THz imaging performance, which is 9 dB higher than that of the previous CMOS detector core circuits with gate-drain capacitors.
已提出一种用于太赫兹以下区域高质量图像的具有并发模式的CMOS探测器。该探测器改善了输出节点处的输出信号耦合特性。添加了一个交叉耦合电容器以隔离漏极和栅极之间的直流偏置。该探测器设计为结合基于共源极操作的180°相移和基于漏极输入的同相输出信号。使用电磁仿真验证了电路布局以及在相位耦合期间交叉耦合电容器中发生的相移。该探测器采用台积电0.25μm混合信号1-多晶硅5-金属层CMOS工艺制造，包括焊盘在内的尺寸为1.13mm×0.74mm。探测器IC包括一个折叠偶极天线、所提出的探测器、一个前置放大器和一个电压缓冲器。使用200GHz回旋管源的测量结果表明，所提出的探测器电压响应度为14.13MV/W，噪声等效功率为34.42pW/√Hz。高检测性能有助于分辨2mm的线宽。就太赫兹成像性能而言，所提出的探测器的信噪比为49dB，比之前带有栅极-漏极电容器的CMOS探测器核心电路高9dB。
