25.5 A 320GHz subharmonic-mixing coherent imager in 0.13µm SiGe BiCMOS
25.5 A 320GHz subharmonic-mixing coherent imager in 0.13µm SiGe BiCMOS
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25.5 采用 0.13μm SiGe BiCMOS 的 320GHz 分谐波混合相干成像器
DOI：
10.1109/isscc.2016.7418092
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
E. Afshari
中科院分区：
文献类型：
--
作者：
Chen Jiang;A. Mostajeran;R. Han;Mohammad Emadi;H. Sherry;A. Cathelin;E. Afshari
太赫兹成像由于其在安全、生物医学和材料表征等方面的新兴应用而受到越来越多的关注。以前的工作已经展示了硅上的太赫兹成像器：在[1]中，作者展示了一个280 GHz的4×4阵列和一个使用肖特基势垒二极管的860 GHz像素;在[2]中，提出了一个0.7至1.1THz的1 k像素相机。遗憾的是，以前的大多数工作都是基于非相干直接检测（图25.5.1），由于输出随输入功率（VRF 2）迅速下降，导致灵敏度低，因此需要非常高的照明电源。利用相干外差检测方案（图25.5.1）可以缓解该问题，在该方案中，太赫兹输入（RF）与本振（LO）信号混频，并产生幅度与VRFVLO成比例的输出。由于LO功率通常显著高于RF，因此灵敏度大大增强。此外，由于输出还携带RF相位信息（φRF），因此可以实现数字波束成形。为了更好地进行比较，NPN晶体管被配置为直接检波器（从发射极注入输入功率）和外差检波器（泵入基极的-20 dBm LO功率）。不同输入功率下的模拟输出电流如图25.5.1所示，我们观察到灵敏度提高了40 dB以上。然而，这种相干感测方案引入了同步发射机（TX）辐射信号和接收机（RX）LO的频率的巨大挑战。幸运的是，锁相太赫兹源已经在硅上得到了验证[3，4]。本文介绍了一种全集成的320 GHz高灵敏度相干成像收发芯片组。
Terahertz imaging has been gaining increasing attention for its emerging applications in security, biomedical and material characterization. Previous works have demonstrated terahertz imagers on silicon: in [1], the authors demonstrated a 280GHz 4×4 array and an 860GHz pixel using Schottky-barrier diodes; in [2], a 0.7-to-1.1THz 1k-pixel camera was presented. Unfortunately, most previous works are based on incoherent direct detection (Fig. 25.5.1), which causes low sensitivity due to the output droping quickly with input power (∝VRF2), and, as a result, need exceedingly high power sources for illumination. This problem can be alleviated by utilizing coherent heterodyne detection scheme (Fig. 25.5.1), in which the terahertz input (RF) mixes with a local oscillation (LO) signal and generates an output with the amplitude proportional to VRFVLO. As the LO power is normally significantly higher than RF, the sensitivity is much enhanced. Moreover, as the output also carries the RF phase information (φRF), digital beamforming is achievable. For a better comparison, an NPN transistor is configured both as a direct detector (input power injected from the emitter) and a heterodyne detector (-20dBm LO power pumped into the base). The simulated output current with different input power is shown in Fig. 25.5.1, in which we observe a sensitivity enhancement of more than 40dB. However, this coherent sensing scheme introduces a great challenge of synchronizing the frequencies of the transmitter (TX) radiated signal and the receiver (RX) LO. Fortunately, phase-locked terahertz sources have been demonstrated on silicon [3,4]. In this paper, a fully integrated 320GHz high-sensitivity coherent-imaging transceiver chipset is demonstrated.
影响因子：
5.4
作者：
Al Hadi, Richard;Sherry, Hani;Pfeiffer, Ullrich R.
通讯作者：
Pfeiffer, Ullrich R.