LCMV beamforming for an L-band antenna array using the Xilinx RFSoC is presented. Implementation of the fully digital beamformer is discussed, including details of the implementation in hardware, High Level Synthesis (HLS), and software. The beamformer is demonstrated for several LCMV cases using an L-band array with eight elements.

Researcher/Author:  

Peizhuo Yang, Jiahao Wang & Koen Mouthaan

Published in:

Conference: 2023 Asia-Pacific Microwave Conference (APMC)

To download the paper, please proceed to:  

10.1109/APMC57107.2023.10439665

In this work, we elucidate the fundamental bias stress reliability mechanism in oxide-semiconductor devices and provided guidelines to improve interface/bulk-induced V TH degradation. We provide further insights into the defect-self compensation effect for the bilayer ITO-IGZO channel. Specifically, how our process approach led to effective passivation of channel defects such as negative-U defects, and ionized-oxygen-vacancy defects. With bilayer ITO-IGZO, we demonstrated 10x negative/positive bias stress (NBS/PBS), and 4x negative bias illumination stress (NBIS) improvement against the conventional mono-IGZO devices. Furthermore, under a low-thermal budget constraint, we implemented a sacrificial replacement gate stress memorization technique to enhance the ferroelectric phase to enable a double-gated (DG) IGZO FeFET. Our reliability-optimized DG ITO-IGZO FeFETs exhibit an enhanced memory window (MW) of 1.7V, excellent memory-write endurance of 10 ⁷ cycles, outstanding memory retention with high I ON /I OFF of 10 ⁶ after 10 ⁴ s, record-low NBS/PNS V TH shift of 30mV, and NBIS V TH shift of 110mV after stress time of 1000s. These devices set a new oxide thin-film transistor (TFT) reliability record making major strides toward highly reliable BEOL logic and memory switches.

Researcher/Author:  

Chun-Kuei Chen, Zefeng Xu, Sonu Hooda, Jieming Pan, Evgeny Zamburg, and Aaron Voon-Yew Thean

Published in:

2023 International Electron Devices Meeting (IEDM)  

Date Added to IEEE Xplore: 07 February 2024

To download the paper, please proceed to:  

10.1109/IEDM45741.2023.10413688

Hydrogels are ideal interfacing materials for on-skin healthcare devices, yet their susceptibility to dehydration hinders their practical use. While incorporating hygroscopic metal salts can prevent dehydration and maintain ionic conductivity, concerns arise regarding metal toxicity due to the passage of small ions through the skin barrier. Herein, an antidehydration hydrogel enabled by the incorporation of zwitterionic oligomers into its network is reported. This hydrogel exhibits exceptional water retention properties, maintaining ≈88% of its weight at 40% relative humidity, 25 °C for 50 days and about 84% after being heated at 50 °C for 3 h. Crucially, the molecular weight design of the embedded oligomers prevents their penetration into the epidermis, as evidenced by experimental and molecular simulation results. The hydrogel allows stable signal acquisition in electrophysiological monitoring of humans and plants under low-humidity conditions. This research provides a promising strategy for the development of epidermis-safe and biocompatible antidehydration hydrogel interfaces for on-skin devices.

Researcher/Author: 

Ke He, Pingqiang Cai, Shaobo Ji, Zihan Tang, Zhou Fang, Wenlong Li, Jing Yu, Jiangtao Su, Yifei Luo, Feilong Zhang, Ting Wang, Ming Wang, Changjin Wan, Liang Pan, Baohua Ji, Dechang Li, and Xiaodong Chen

Published in:

Advanced Materials

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https://doi.org/10.1002/adma.202311255

Efforts to design devices emulating complex cognitive abilities and response processes of biological systems have long been a coveted goal. Recent advancements in flexible electronics, mirroring human tissue’s mechanical properties, hold significant promise. Artificial neuron devices, hinging on flexible artificial synapses, bioinspired sensors, and actuators, are meticulously engineered to mimic the biological systems. However, this field is in its infancy, requiring substantial groundwork to achieve autonomous systems with intelligent feedback, adaptability, and tangible problem-solving capabilities. This review provides a comprehensive overview of recent advancements in artificial neuron devices. It starts with fundamental principles of artificial synaptic devices and explores artificial sensory systems, integrating artificial synapses and bioinspired sensors to replicate all five human senses. A systematic presentation of artificial nervous systems follows, designed to emulate fundamental human nervous system functions. The review also discusses potential applications and outlines existing challenges, offering insights into future prospects. We aim for this review to illuminate the burgeoning field of artificial neuron devices, inspiring further innovation in this captivating area of research.

Researcher/Author:  

Ke He, Cong Wang, Yongli He, Jiangtao Su & Xiaodong Chen

Published in:

Chemical Reviews 2023, 123, 23, 13796-13865 (Review)

To download the paper, please proceed to:  

10.1021/acs.chemrev.3c00527

Current references are fundamental building blocks in sensor interfaces and other analog circuitries [1]–[9]. In applications with low-cost targets, their area and testing effort need to be minimized, and trimming must be eliminated. In power-constrained systems, their net power (i.e., not going into their output bias current IREF) and minimum supply voltage Vmin need to be kept low, so as to minimize the power burden and remove supply scaling limitations at the system level. Unfortunately, lower net power generally leads to poorer accuracy due to PVT variations, requiring innovation to make the power-accuracy tradeoff more favorable while avoiding trimming.

Researcher/Author:  

Luigi Fassio, Hoang Hong Hanh, Massimo Alioto

Published in:

2023 IEEE Asian Solid-State Circuits Conference (A-SSCC)

Date Added to IEEE Xplore: 18 December 2023

To download the paper, please proceed to:  

10.1109/A-SSCC58667.2023.10347973

An L-band antenna array with eight elements and full digital beamforming using the Xilinx RFSoC is presented. Details of the implementation in the hardware, high level synthesis, and the software are provided. Digital beamforming is at the element level without the need for phase shifters or true time delays.

Researcher/Author:  

Peizhuo Yang, Gong Chen & Koen Mouthaan

Published in:

Conference: 2023 IEEE International Symposium On Antennas And Propagation (ISAP)

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http://dx.doi.org/10.1109/ISAP57493.2023.10389090

A low-cost L-band antenna with reconfigurable quad-polarization is presented. The antenna consists of four identical radiating elements. Each element comprises two stacked rectangular patches to achieve more than 10% bandwidth. Through proper phasing of the four elements, the antenna can realize two orthogonal linear polarizations and two circular polarizations. To demonstrate the concept, an antenna is realized using FR-4 substrate. The measured 10-dB input return loss bandwidth is 11%. And the measured 3-dB gain bandwidth is from 1.21 GHz to 1.36 GHz, with a maximum gain of 8.8 dBi for both linear polarization and circular polarization.

Researcher/Author:  

Gong Chen, Fujiang Lin & Koen Mouthaan

Published in:

2023 IEEE International Symposium On Antennas And Propagation (ISAP)

Date Added to IEEE Xplore: 22 January 2024

To download the paper, please proceed to:  

10.1109/ISAP57493.2023.10388982