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This article presents a compact meta-surface (MS) based antenna with dual-band operation for 5G applications. The MS-based antenna consists of a layer of MSs on the top of a single-band microstrip patch antenna. The dual-band operation is achieved by adding the MS layer at a height of 0.089λ 0 , where λ 0 is the free space wavelength at the lower resonant frequency. The patch antenna is designed on a 21 mm × 20 mm × 0.508 mm substrate. The MS is comprised of two metallic layers printed on the top and bottom of a 1.575 mm Rogers 5880 substrate. The overall thickness of the proposed antenna is 0.27λ 0. The proposed antenna is fabricated and tested. The configuration achieves dual-band features with bandwidth, and gain of 1 GHz, and 10 dBi at 26.4 GHz, 800 MHz, and 9.6 dBi at 27.6 GHz, respectively. Also, a high radiation efficiency of 91.2 % is achieved at the frequency bands. [ABSTRACT FROM AUTHOR]

In this study, a resistor-loaded wideband conformal metamaterial absorber has been designed, fabricate, and analyzed experimentally. The proposed absorber consists of lumped resistors loaded on cross-shaped resonators at the top side of the flexible substrate and copper metal film separated by flexible foam on the substrate's backside. The total thickness of the absorber is 0.07λ o , where λ o is the lowest absorption frequency. The simulated results exhibited absorption from 3.25 − 13.6 GHz (absorption bandwidth 123%). The wideband absorption mechanism of the absorber was analyzed through the equivalent circuit model and parametric study. The designed structure has been tested on the planar and curved surfaces and measured the results. The simulated and experimental results have good agreement between them. The designed absorber can be suitable for scientific and military applications as of its wideband absorption bandwidth, polarization-insensitive, and conformability. [ABSTRACT FROM AUTHOR]

• A novel model of SERS was designed using an innovative glass and nano-gold. • The proposed model can detect the circulating tumor-derived exosomes in HCC cases. • The new SERS model could identify HCC patients non-invasively with high accuracy. • The RS exosomal analysis had 95 % sensitivity and 100 % specificity for detecting HCC. The current hepatocellular carcinoma (HCC) diagnostic approaches lack adequate sensitivity and specificity. So, this study was performed to develop an innovative model of surface-enhanced Raman spectroscopy (SERS) that can detect HCC patients by identifying the circulating tumor-derived exosomes. Sixty participants, including normal controls, hepatitis C virus (HCV)-infected patients, and HCV-associated HCC patients, had their whole blood samples and exosomes separated from these samples analyzed using Raman spectroscopy (RS). A revolutionary model of SERS, based on an innovative glass and nano-gold, was designed to directly identify exosomes. Its measurements were simulated by Comsol Multiphysics (5.6). The RS examination of the whole blood samples revealed no Raman peaks. Yet, the isolated exosomes from these samples generated Raman peaks at 400 and 1000 cm−1 wavenumbers in the HCV group. A Raman shift was detected in HCC patients at 812, 852, and 878 cm−1 wavenumbers with intensity ratios of 120, 130, and 60, respectively. The RS had a sensitivity and specificity of 95 % and 100 %, respectively, for detecting HCC. However, the newly-designed SERS was able to identify the HCC-derived exosomes, at 812 and 878 cm−1 wavenumbers, with boosted intensity ratios of 9*106 and 4*106, respectively, in the whole blood samples. The newly-developed SERS model has the potential to detect HCC patients through recognizing the tumor-derived exosomes non-invasively, with high accuracy, and without the need for laborious exosomal separation. Nonetheless, bringing this technology into the clinic demands the establishment of spectral databases and their validation using the current gold standards. [ABSTRACT FROM AUTHOR]

A flexible paper based and dual-band antenna is designed for UMTS service (1.9 GHz) and WiMAX services (5.8 GHz). Flexible paper is used as a substrate for the printed antenna. Expanded graphite ink is used to enable printing the antenna on the substrate. The antenna has been designed, simulated, fabricated, and measured. Steps of preparing the conductive printed ink and fabrication of the antenna have been discussed. The conductivity of the printed antenna is measured to be 1 × 104 S/square and the thickness is also measured with an average of 30 µm. Through the whole paper, good agreement between simulated and measured results is satisfied. In addition to the achieved flexibility, the antenna has demonstrated good measurement results. First, the antenna has a bandwidth of 300 MHz at 1.9 GHz and 400 MHz at 5.8 GHz with fractional bandwidth of 15.7% and 6.8% at the both bands, respectively. Second, the measured antenna radiation pattern has indicated that it is omnidirectional at 1.9 GHz and approximately omnidirectional at 5.8 GHz. Third, The antenna gain is 1.266 dB and 0.512 dB at the two bands, respectively. Finally, the antenna's efficiency at the both bands is 35% and 55%. [ABSTRACT FROM AUTHOR]