A 20.8-Gbps Dual-Carrier Wireless Communication Link in 220-GHz Band

With the successful demonstration of terahertz(THz)high-speed wireless data transmission,the THz frequencies are now becoming a worth candidate for post-5G wireless communications.On the other hand,to bring THz communications a step closer to real scenario application,solving high data rate realtime transmission is also an important issue.This paper describes a 220-GHz solid-state dual-carrier wireless link whose maximum transmission real-time data rates are 20.8 Gbps(10.4 Gbps per channel).By aggregating two carrier signals in the THz band,the contradiction between high real-time data rate communication and low sampling rate analog-to-digital(ADC)and digital-to-analog converter(DAC)is alleviated.The transmitting and receiving front-ends consist of 220-GHz diplexers,220-GHz sub-harmonic mixers based on anti-parallel Schottky barrier diodes,G-band low-noise amplifiers(LNA),WR-4.3 band high-gain Cassegrain antennas,high data rates dual-DAC and-ADC baseband platform and other components.The low-density parity-check(LDPC)encoding is also realized to improve the bit error rate(BER)of the received signal.Modulated signals are centered at 214.4 GHz and 220.6 GHz with-11.9 dBm and-13.4 dBm output power for channel 1 and 2,respectively.This link is demonstrated to achieve 20.8-Gbps real-time data transmission using 16-QAM modulation over a distance of 1030 m.The measured signal to noise ratio(SNR)is 17.3 dB and 16.5 dB,the corresponding BER is 8.6e-7 and 3.8e-7,respectively.Furthermore,4K video transmission is also carried out which is clear and free of stutter.The successful transmission of aggregated channels in this wireless link shows the great potential of THz communication for future wireless high-rate real-time data transmission applications.

A novel neuroprotective method against ischemic stroke by accelerating the drainage of brain interstitial fluid

Ischemic stroke is a leading cause of death and disability worldwide.Inflammatory response after stroke determines the outcome of ischemic injury.A recent study has reported an efficient method,epidural arterial implantation(EAI),for accelerating interstitial fluid(ISF)drainage,which provides a promising strategy to clear pro-inflammatory cytokines in the brain extracellular space(ECS).In this study,the method of EAI was modified(m-EAI)to control its function of accelerating the ISF drainage at different time points following ischemic attack.The neuroprotective effect of m-EAI on ischemic stroke was evaluated with the transient middle cerebral artery occlusion(tMCAO)rat model.The results demonstrated the accumulation of IL-1β,IL-6,and TNF-αwas significantly decreased by activating m-EAI at 7 d before and immediately after ischemic attack in tMCAO rats,accompanied with decreased infarct volume and improved neurological function.This study consolidates the hypothesis of exacerbated ischemic damage by inflammatory response and provides a new perspective to treat encephalopathy via brain ECS.Further research is essential to investigate whether m-EAI combined with neuroprotective drugs could enhance the therapeutic effect on ischemic stroke.