| 讲座信息 Recent Progress on THz Electronics: Chip-Scale Wave-Matter Interactions and Large Active Arrays
Professor Ruonan Han from MIT 时 间：2017年8月16日（周三）10:00-11:30
地 点：张江校区微电子楼369会议室 Abstract In this talk, we present new opportunities and challenges in the THz integrated electronics. One interesting direction in particular, is the on-chip sensing and metrology microsystems utilizing wave-matter interactions. As one example, weak photons at microwave to THz frequencies can excite rotational modes of polar gas molecules. The associated absorption normally reaches intensity peak in the low THz range and has ultra-narrow spectral linewidth (Q=105~106). A THz spectrometer is therefore a powerful tool for gas sensing with wide detection range, high sensitivity and specificity. On this end, we have developed a CMOS spectrometer, which is based on a pair of counter-propagating frequency-comb spectra. By introducing high-parallelism and simultaneous transmit/receive operations, the chip seamlessly covers a 220-to-320GHz band while increasing the scanning speed by 20x, compared to prior arts. With its record total radiated power (5.2 mW) and sensitivity (NF=15~20 dB), our spectrometer demonstrates ppm-level (3 ppm for HCN) sensitivity for un-concentrated gas samples. Lastly, some other recent works, including a chip-scale “molecular” clock and a quantum magnetic sensor—both on CMOS, will also be introduced. In the second part of this talk, we show some efforts towards an on-chip THz “laser”. Due to the smaller wavelength at increasing frequencies, it is expected that a high-density, coherent radiator array can be built in a single chip, enabling large-scale power combining and narrow beam width. For example, inside a 10-mm2 chip area, integration of more than 1000 coherent radiators at 1 THz should be possible, assuming an optimal unit pitch of half-wavelength. This however means each active radiator, even if it works at 1 THz, can only occupy a tiny ~100×100-μm2 area. To address such challenges, we introduce a new scalable array of compact multi-functional electromagnetic structures—each simultaneously behaves as oscillator, frequency multiplier, frequency filter and antenna. In a 130-nm SiGe BiCMOS process, a 1.01-THz radiation source consisting of 42 oscillators and 91 coherent antennas is implemented in only 1-mm2 chip area. It generates a total radiated power of ~0.1mW and an effective isotropically radiated power (EIRP) of 20mW (thanks to a narrow beam width <10°). These have improved the prior records of silicon mid-THz work by 10x and 200x. BIO:
Professor Ruonan Han received his Ph.D. degree in electrical and computer engineering from Cornell University in 2014. Prior to that, he received his B.Sc. degree in microelectronics from Fudan University in 2007 and M.Sc. degree in electrical engineering from the University of Florida in 2009. In 2014, he was appointed as an assistant professor by the Department of Electrical Engineering and Computer Science at Massachusetts Institute of Technology. The research of Prof. Han has focused on millimeter-wave and terahertz integrated circuits and microsystems for new sensing technologies in biomedical diagnosis, homeland security, and industrial quality control. He was the recipient of the IEEE Solid-State Circuits Society (SSCS) Pre-Doctoral Achievement Award, the IEEE Microwave Theory and Tech. Society (MTT-S) Graduate Fellowship Award, the Best Student Paper Award (2nd) of two IEEE RFIC symposia (2012 and 2017), and the Director’s Best Thesis Award at Cornell University. He currently holds MIT E. E. Landsman (1958) Career Development Chair Professorship and is the winner of the National Science Foundation (NSF) CAREER Award. 联系人：徐鸿涛 |