热点论文与带您领略5G/6G电子器件和太赫兹方面的最新进展——图书馆前沿文献专题推荐服务（28）

2020-11-20

 

领域一 宽带随机光电振荡器

Broadband random optoelectronic oscillator
Zengting Ge, etc.
Nature Communications, 2020

Random scattering of light in transmission media has attracted a great deal of attention in the field of photonics over the past few decades. An optoelectronic oscillator (OEO) is a microwave photonic system offering unbeatable features for the generation of microwave oscillations with ultra-low phase noise. Here, we combine the unique features of random scattering and OEO technologies by proposing an OEO structure based on random distributed feedback. Thanks to the random distribution of Rayleigh scattering caused by inhomogeneities within the glass structure of the fiber, we demonstrate the generation of ultra-wideband (up to 40 GHz from DC) random microwave signals in an open cavity OEO. The generated signals enjoy random characteristics, and their frequencies are not limited by a fixed cavity length figure. The proposed device has potential in many fields such as random bit generation, radar systems, electronic interference and countermeasures, and telecommunications.
 

领域二 基于纳米光纤网络的高精度表皮射频天线在无线可伸缩多功能电子领域的应用

High precision epidermal radio frequency antenna via nanofiber network for wireless stretchable multifunction electronics
Yufei Zhang, etc.
Nature Communications, 2020

Recently, stretchable electronics combined with wireless technology have been crucial for realizing efficient human-machine interaction. Here, we demonstrate highly stretchable transparent wireless electronics composed of Ag nanofibers coils and functional electronic components for power transfer and information communication. Inspired by natural systems, various patterned Ag nanofibers electrodes with a net structure are fabricated via using lithography and wet etching. The device design is optimized by analyzing the quality factor and radio frequency properties of the coil, considering the effects of strain. Particularly, the wireless transmission efficiency of a five-turn coil drops by approximately only 50% at 10 MHz with the strain of 100%. Moreover, various complex functional wireless electronics are developed using near-field communication and frequency modulation technology for applications in content recognition and long-distance transmission (>1 m), respectively. In summary, the proposed device has considerable potential for applications in artificial electronic skins, human healthcare monitoring and soft robotics.
 

领域三 InGaAs mHEMT技术中的300GHz宽带功率放大器毫米波单片集成电路

Broadband 300-GHz Power Amplifier MMICs in InGaAs mHEMT Technology
Laurenz John, etc
IEEE Transactions on Terahertz Science and Technology, 2020, 10(3): 309 - 320

In this article, we report on compact solid-state power amplifier (SSPA) millimeter-wave monolithic integrated circuits (MMICs) covering the 280-330-GHz frequency range. The technology used is a 35-nm gate-length InGaAs metamorphic high-electron-mobility transistor (mHEMT) technology. Two power amplifier MMICs are reported, based on a compact unit amplifier cell, which is parallelized two times using two different Wilkinson power combiners. The Wilkinson combiners are designed using elevated coplanar waveguide and air-bridge thin-film transmission lines in order to implement low-loss 70-Ω lines in the back-end-of-line of this InGaAs mHEMT technology. The five-stage SSPA MMICs achieve a measured small-signal gain around 20 dB over the 280-335-GHz frequency band. State-of-the-art output power performance is reported, achieving at least 13 dBm over the 286-310-GHz frequency band, with a peak output power of 13.7 dBm (23.4 mW) at 300 GHz. The PA MMICs are designed for a reduced chip width while maximizing the total gate width of 512 μm in the output stage, using a compact topology based on cascode and common-source devices, improving the output power per required chip width significantly.
 

领域四 室内阻塞效应和可视接入并发的太赫兹网络干扰和覆盖分析

Interference and Coverage Analysis for Terahertz Networks with Indoor Blockage Effects and Line-of-Sight Access Point Association
Yongzhi Wu, etc.
IEEE Transactions on Wireless Communications, 2020

Providing high-bandwidth and fast-speed links, wireless local area networks (WLANs) in the Terahertz (THz) band have huge potential for various bandwidth-intensive indoor applications. However, due to the specific phenomena in the THz band, including severe reflection loss, indoor blockage effects, multi-path fading, the analysis on the interference and coverage probability at a downlink is challenging. In this paper, indoor blockage effects caused by the walls and human bodies are analyzed. Next, a statistical THz channel model is proposed to characterize the THz indoor propagation. In light of these, the moment generating functions of the aggregated interference and theoretical expressions for the mean interference power are derived. As a result, the approximated coverage probability and average network throughput are derived. Extensive numerical results show that for the nearest access point (nearest-AP) user association scheme, the optimal AP density is 0.15/m2, which results in the coverage probability reaches 93% and the average network throughput is 30 Gbps/m2. In addition, by adopting a novel line-of-sight access point (LoS-AP) user association mechanism, the coverage probability and the average network throughput can be further improved by 3 percent and 2 Gbps/m2, respectively.