Reconfigurable Surface Wave Fluid Antenna for Spatial MIMO Applications

This paper presents the design of a surface wave fluid antenna which can realizes beamshaping and spatial diversity for MIMO applications. The proposed design only required one RF input to achieve spatial diversity when comparing to the conventional multiple RF input ports approaches. The surface wave fluid antenna is designed for the millimeter-wave 5G mobile communications band from 24 to 28 GHz. The simulation results show that the radiation direction of the antenna can be controlled by changing the position of the fluid metal radiator

Beam-steering Surface Wave Fluid Antennas for MIMO Applications

This paper proposed to use surface wave fluid antennas to realize beam-steering functionality and spatial diversity for MIMO applications. By utilizing the advantage of the non-radiating feature of surface wave propagation, in contrast to the conventional multiple RF input ports approach reported, the proposed design only required one RF input to achieve the spatial diversity. The surface wave fluid antenna is designed to work in the millimeter-wave frequency band from 20 to 26.5 GHz. The preliminary results show that the radiation direction of the antenna can be controlled by changing the position of the fluid metal radiator

Radiation Pattern Diversified Single-Fluid-Channel Surface-Wave Antenna for Mobile Communications

In this paper, an antenna design that combines surface wave and fluidic reconflgurable techniques was presented. The antenna operates in a wide frequency range from 23 to 38 GHz, which covers the Very High 5G Frequency band in the US, Europe, China, Japan, and Korea. In this design, only one RF input port is needed to achieve diversity when compared with the conventional multiple RF input ports approaches. From the simulation results, the proposed antenna design could change its radiation pattern based on the position of the fluid radiator. Such radiation pattern diversity feature can deal with channel interference issues

Radiation Pattern Diversified Double-Fluid-Channel Surface-Wave Antenna for Mobile Communications

In this paper, we present an antenna design for millimeter wave 5G applications. The proposed antenna has a wide working frequency range from 23.5 GHz to 36.5 GHz. This can cover the millimeter wave 5G frequency band in most countries. The design is simple and will mitigate the difficulty when implementing in a wireless system with reconfigurable capability. The antenna design only needs a single RF port as input to achieve radiation pattern diversity by moving the fluid radiators in its two channels. With the radiation pattern diversity capability, the problem like weak signal strength and inter channel interference can be eased.The design shows higher dynamic range of patterns turning when compare to the previous work on single-channel surface-wave antenna with the purpose of wider angular coverage with multichannel design. The comparison result of the two designs will also be provided in this paper

Toward Liquid Reconfigurable Antenna Arrays for Wireless Communications

Liquid-based antennas promise to overcome crucial limitations of traditional solid-based ones. Here, we describe different liquid antenna technologies that can be used to build arrays with the unprecedented flexibility and adaptivity needed to enable an evolution in wireless communications. We focus on two approaches that use either metallic or non-metallic liquids as radiating elements. In both cases, the resulting devices can be reconfigured dynamically, thus modifying the radiation parameters of an antenna in real time in an inexpensive way. To that end, we describe some of the challenges which arise when integrating such antennas as part of a whole communication system. We discuss the solutions adopted in some initial prototypes and summarize some of the problems that need to be solved to pave the way for integrating fully reconfigurable liquid antenna arrays in wireless communication systems

Development of Millimeter-wave FMCW Vertical-looking Entomological Radar System

This work presents a frequency modulated continuous wave (FMCW) millimeter-wave vertical-looking radar (VLR) system. The proposed system operates at 34.5 GHz and can continuously detect targets flying at a maximum of 200m above the ground. In field tests, it measures the target's displacement direction, moving speed, mass and body shape. An Altera Stratix IV FPGA is utilized for signal processing of the FMCW radar signal. A cosecant squared pattern leaky wave antenna is suggested to detect the targets with constant power and reduce the data processing load in real time system

Polysaccharides from wolfberry prevents corticosterone-induced inhibition of sexual behavior and increases neurogenesis

Lycium barbarum, commonly known as wolfberry, has been used as a traditional Chinese medicine for the treatment of infertility and sexual dysfunction. However, there is still a scarcity of experimental evidence to support the pro-sexual effect of wolfberry. The aim of this study is to determine the effect of Lycium barbarum polysaccharides (LBP) on male sexual behavior of rats. Here we report that oral feeding of LBP for 21 days significantly improved the male copulatory performance including increase of copulatory efficiency, increase of ejaculation frequency and shortening of ejaculation latency. Furthermore, sexual inhibition caused by chronic corticosterone was prevented by LBP. Simultaneously, corticosterone suppressed neurogenesis in subventricular zone and hippocampus in adult rats, which could be reversed by LBP. The neurogenic effect of LBP was also shown in vitro. Significant correlation was found between neurogenesis and sexual performance, suggesting that the newborn neurons are associated with reproductive successfulness. Blocking neurogenesis in male rats abolished the pro-sexual effect of LBP. Taken together, these results demonstrate the pro-sexual effect of LBP on normal and sexually-inhibited rats, and LBP may modulate sexual behavior by regulating neurogenesis. © 2012 Lau et al.published_or_final_versio

On the antenna for long range low power geographical monitoring IoT network

An Internet of Things (IoT) network has been developed and tested in the BaZheXiang area in Sichuan, China. The network will be used to monitor the slopes for the potential landslides. The existing Wi-Fi network required more than five hops before reaching the temporary data centre in the hut which is 8km away from the data centre. However, the new system only requires maximum three hops, the real-time geological information of the slope can be delivered to the data centre at the main water dam

Aharonov-Bohm interference in topological insulator nanoribbons

Topological insulators represent novel phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport measurements. Recently, Bi2Se3 and related materials have been proposed as three-dimensional topological insulators with a single Dirac cone on the surface and verified by angle-resolved photoemission spectroscopy experiments. Here, we show unambiguous transport evidence of topological surface states through periodic quantum interference effects in layered single-crystalline Bi2Se3 nanoribbons. Pronounced Aharonov-Bohm oscillations in the magnetoresistance clearly demonstrate the coverage of two-dimensional electrons on the entire surface, as expected from the topological nature of the surface states. The dominance of the primary h/e oscillation and its temperature dependence demonstrate the robustness of these electronic states. Our results suggest that topological insulator nanoribbons afford novel promising materials for future spintronic devices at room temperature.Comment: 5 pages, 4 figures, RevTex forma

Why all the fuss about 2D semiconductors?

Graphene is no longer alone; a family of atomically thin 2D semiconductors has emerged. Optoelectronics and photonics applications are in their experimental infancy but the future holds much promise.Comment: Commentary article, 1 figure, 1 tabl