More Like this

1. Near 100% external quantum efficiency 1550-nm broad spectrum photodetector

   https://doi.org/10.1364/OE.447091  

   Shen, Yang; Xue, Xingjun; Jones, Andrew_H; Peng, Yiwei; Gao, Junyi; Tzu, Ta_Ching; Konkol, Matt; Campbell, Joe_C (January 2022, Optics Express)

   We report InGaAs/InP based p-i-n photodiodes with an external quantum efficiency (EQE) above 98% from 1510 nm to 1575 nm. For surface normal photodiodes with a diameter of 80 µm, the measured 3-dB bandwidth is 3 GHz. The saturation current is 30.5 mA, with an RF output power of 9.3 dBm at a bias of −17 V at 3 GHz. 

   more » « less
2. A <5 dB NF, > 17 dBm OP _{1 dB} F-Band GaN-on-SiC HEMT LNA with a Monolithic Substrate-Integrated Waveguide Filter

   https://doi.org/10.1109/IMS40175.2024.10600353  

   Thome, Fabian; Schwantuschke, Dirk; Brückner, Peter; Wang, Xiaopeng; Hwang, James_C M; Quay, Rüdiger (June 2024, IEEE)

   This paper demonstrates the monolithic integration of a substrate-integrated waveguide bandpass filter (BPF) and a low-noise amplifier (LNA) at F-band, fabricated in a 70-nm GaN-on-SiC technology. The three-stage LNA alone achieves a state-of-the-art average noise figure of 3.6 dB over 87–115 GHz. The LNA + BPF exhibits a peak gain of 13.6 dB over a 3 dB bandwidth of 17 GHz from 104 to 121 GHz. The average noise figure is 4.9 dB over 87–115 GHz. The OP1 dB and saturated output power are 17.6dBm and >20 dBm, respectively. 

   more » « less
3. CsPbBr ₃ Perovskite Nanocrystals for Photocatalytic [3+2] Cycloaddition

   https://doi.org/10.1002/cssc.202301060  

   Lin, Yixiong; Yan, Yong (January 2024, ChemSusChem)

   Abstract Visible‐light‐induced halide‐exchange between halide perovskite and organohalide solvents has been studied in which photoinduced electron transfer from CsPbBr₃nanocrystals (NCs) to dihalomethane solvent molecules produces halide anions via reductive dissociation, followed by a spontaneous anion‐exchange. Photogenerated holes in this process are less focused. Here, for CsPbBr₃in dibromomethane (DBM), we discover that Br radical (Br⋅) is a key intermediate resulting from the hole oxidation. We successfully trapped Br⋅ with reported methods and found that Br⋅ is continuously generated in DBM under visible light irradiation, hence imperative for catalytic reaction design. Continuous Br⋅ formation within this halide‐exchange process is active for photocatalytic [3+2] cycloaddition for vinylcyclopentane synthesis, a privileged scaffold in medicinal chemistry, with good yield and rationalized diastereoselectivity. The NC photocatalyst is highly recyclable due to Br‐based self‐healing, leading to a particularly economic and neat heterogeneous reaction where the solvent DBM also acts as a co‐catalyst in perovskite photocatalysis. Halide perovskites, notable for efficient solar energy conversion, are demonstrated as exceptional photocatalysts for Br radical‐mediated [3+2] cycloaddition. We envisage such perovskite‐induced Br radical strategy may serve as a powerful chemical tool for developing valuable halogen radical‐involved reactions. 

   more » « less
4. A 2-Way W-Band Power Amplifier With an Isolated Combining Output Network for Power Back-Off Efficiency Enhancement in 16-nm FinFet Technology

   https://doi.org/10.1109/LSSC.2024.3426336  

   Ibrahim, Yahia; Niknejad, Ali (January 2024, IEEE Solid-State Circuits Letters)

   This paper introduces a W-band sequential power amplifier (PA) \cite{0th} with a novel output network designed to minimize passive and combiner losses, while reducing the overall footprint compared to conventional sequential and Doherty PAs\cite{1st}. An isolated output combiner sums two PAs operating in two different modes: the main amplifier operates in class AB and the auxiliary amplifier operates in class C. The measured PA achieves a saturated output power ($$\mathbf{P_{sat}}$$) of 13 dBm and a gain of 12.5 dB with 3 dB bandwidth from 79.5 GHz to 94.5 GHz. Additionally, it demonstrates a peak Power Added Efficiency (PAE) of 19.4\% and a 14.6\% PAE at 6 dB power back-off (PBO) at 87.5 GHz. Furthermore, the PA achieves a data rate of 12 Gb/s for a 16QAM signal with an average output power of 5 dBm, an average PAE of 10\%, and an EVM (RMS) of -20 dB. The PA was fabricated in 16-nm FinFet technology with core area of 0.15mm$^2$. To the authors’ knowledge, this PA has the highest PAE at 6dB PBO for CMOS PAs operating in the W-Band. 

   more » « less
5. A 49-63 GHz Phase-locked FMCW Radar Transceiver for High Resolution Applications

   Liu, Xuyang; Maktoomi, Md Hedayatullah; Alesheikh, Mahdi; Heydari, Payam; Aghasi, Hamidreza (October 2023, IEEE European Solid State Circuits Conference)

   TPC of IEEE ESSCIRC Conference (Ed.)

   This paper presents an mmWave FMCW radar that can achieve sub-centimeter-scale range resolution at 14- GHz chirp-bandwidth while maintaining the radar range beyond 50 meters. To meet the requirements on power efficiency, chirp linearity, and signal-to-noise ratio (SNR), a phase-locked steppedchirp FMCW radar architecture is introduced. Specifically, a fully integrated radar transceiver comprising an interleaved frequency-segmented phase-locked transmitter and a segmented receiver architecture with high sensitivity is presented. The proposed design addresses the limitations of conventional typeII phase-locked loops (PLLs) in extending the radar bandwidth across multiple sub-bands with identical chirp profiles. Fabricated in a 22nm FD-SOI technology, the prototype chip comprises two sub-bands with 14 GHz of free-running bandwidth and 10 GHz of phase-locked bandwidth. The system achieves -101.7 dBc/Hz phase noise at 1 MHz offset, 8 dBm of effective isotropic radiated power (EIRP), 10 dB noise figure (NF), and 362.6 mW collective power consumption of transmitter and receiver arrays. 

   more » « less