Eighteen-Element Antenna for Metal-Rimmed Smartphone Sub-6 GHz LTE42 Band Applications

Due to the limited space and large mutual coupling levels,the design of sub-6 GHz massive Multi-Input Multi-Output(m-MIMO)smartphone antenna system attracts antennas’designers and engineers worldwide.Therefore,this paper presents 18-element m-MIMO antenna system that covers the long-term evolution 42(LTE42)frequency band(3.4–3.6 GHz)for the fifth generation(5G)applications in metallic frame smartphones.The proposed array system is etched on the long sides of a metal rim of the mobile chassis symmetrically,which is electrically connected to the system ground plane with zero ground clearance.A low-profile frame of height 7 mm(λ/12.3)is symmetrically placed below&above the ground system level.The two frame parts(above/below the ground level)are utilized separately for the implantation of the antenna elements to achieve good space exploitation and perfect pattern diversity between elements.Orthogonal feeds are used to further increase the level of the isolation where each antenna element above the ground level is fed by a 50-ohm microstrip line,and each antenna element below the ground level is fed by a 50-ohm coplanar waveguide(CPW).The proposed antenna structure is a capacitive coupled-fed open-slot antenna with a small footprint area of 12×3.5 mm2(λ/7.2×λ/24.5,whereλrepresents the free space wavelength at 3.5 GHz).A small coupling L-shaped strip provides a capacitive coupling for the proposed 5G antenna structure.To establish the contribution of the proposed 18-element m-MIMO,the prototype of the proposed system was manufactured and successfully measured.Both measured and simulated results are shown to be in good agreement.This proves that the proposed antenna provides coverage for the LTE42 band(3.4–3.6 GHz)with acceptable isolation and efficiency.Moreover,the performance of the proposed m-MIMO were further verified via channel capacity calculation and the envelope correlation coefficient(ECC)measurement.Based on that,the proposed m-MIMO is shown to provide a desirable performance for all mMIMO parameters while it owns the largest MIMO order in mobile terminals in the open literature.

Blend Films of Chitosan/Starch

The technique of simultaneous G banding and in situ hybridization has been developed in plants for the first time. Using this technique, RFLP marker umc58 closely linked with the hm1 gene dictating Helminthosporium carbonum susceptibility1 was localized onto 1L3 (chromosome 1, long arm, the third band from the centromere to the end of the arm), 5L5 and 9L5. The results demonstrated that umc58 was a triplicated sequence. It was deduced that umc58 probably was in a duplicated region that includes a part of Helminthosporium carbonum susceptibility genes (hm1 and hm2), as the hybridization sites of umc58 in chromosomes 1 and 9 were those at which the genes localize. The techniques of simultaneous G banding and ISH in plants are discussed.

Non-Adiabatic Phonon Dispersion of Metallic Single-Walled Carbon Nanotubes

Non-adiabatic effects can considerably modify the phonon dispersion of low-dimensional metallic systems.Here,these effects are studied for the case of metallic single-walled carbon nanotubes using a perturbative approach within a density-functional-based non-orthogonal tight-binding model.The adiabatic phonon dispersion was found to have logarithmic Kohn anomalies at the Brillouin zone center and at two mirror points inside the zone.The obtained dynamic corrections to the adiabatic phonon dispersion essentially modify and shift the Kohn anomalies as exemplified in the case of nanotube(8,5).Large corrections have the longitudinal optical phonon,which gives rise to the so-called G-band in the Raman spectra,and the carbon hexagon breathing phonon.The results obtained for the G-band for all nanotubes in the diameter range from 0.8 to 3.0 nm can be used for assignment of the high-frequency features in the Raman spectra of nanotube samples.