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A rectangular microstrip patch (RMSP) antenna is designed to be used in a two-element Multi-Input Multi-Output (MIMO) antennas at which they operate at 5.8 GHz. The two antennas are positioned opposite to each other with a separation of 10 mm (0.2 λ 0) from their radiating edges. A novel uni-conductor electromagnetic bandgap (UC-EBG) periodic cells are introduced in this paper as effective barriers for surface waves compared to the conventional UC-EBG. Each unit cell has a compact size area 7.3 × 5.8 mm2 where it is 20% more compact than the conventional cell. Two of the proposed modified EBG periodic cells are placed in-between the two antennas causing an excellent reduction in the coupled power of 46 dB. This strong isolation definitely enhances the performance of antennas in MIMO communication systems, where 0.0001 and 0.03 values for correlation coefficient have obtained from S-parameters and far-field information, respectively, due to this strong isolation. [ABSTRACT FROM AUTHOR]

Abstract In this paper, an efficient technique proposed for surface wave filtering in radar array antennas. The filtering reduced the correlation between high directive TX/RX array antennas. The filtering has been done using a small defected ground filter that achieves more than 20 dB isolation between the two antennas with a very close separation between the two antennas (less than 0.06 λ 0). The presented results confirm the advantage of the applied technique in reducing the correlation coefficient between the two antennas to less than 0.005. The results demonstrate that 99.68% of coupled power can be reduced. The integrated isolated radar array antennas have been studied theoretically, simulated using electromagnetic simulation, and measured experimentally. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the experimental verification of the tunable characteristics of a ferrite composite right/left handed coupled line coupler. The coupler is designed using two coupled CRLH-CRLH transmission lines. The coupler is designed to demonstrate equal through and backward coupling. The novel coupler has been designed and realized in coplanar waveguide configuration on a ferrite substrate. The tunable characteristics are achieved by changing the applied DC magnetic bias to the ferrite substrate. The measurement results reveal that the coupler's fractional bandwidth can be tuned from 29% to 69% by varying the applied DC magnetic bias from 1000 Oe to 1750 Oe. Within the tunable bandwidth, the maximum backward coupling is −5 dB. The coupler has high forward coupling isolation, close to −30 dB at its centre operating frequency. In addition to its tuning capability, the coupler has the advantages of its compact size; it has the length of 11.5 mm and not-so-tight line separations of 2.5 mm. Furthermore the coupler only requires low DC magnetic bias. [ABSTRACT FROM AUTHOR]

In this paper, the time domain analysis of an Ultra Wide Band antenna flexible circular monopole antenna is presented. The antenna is fabricated on liquid crystalline polymer flexible substrate with a compact geometry that makes it suitable for wearable applications under different bending conditions. The antenna is fed by coplanar waveguide transmission line and has a compact total size of 40 × 22 mm 2 . Moreover, the antenna has good radiation efficiency (97%) over the bandwidth. The presented antenna has a good performance over the operating spectrum for straight and bending configurations. The design principals along with simulation and experimental results are presented in this contribution. [ABSTRACT FROM AUTHOR]

In this paper, two different triple band dipole antennas loaded by new modified composite right left handed cell are presented. The modified cell can introduce large electrical length in small size. Thus, the two antennas are designed with smaller operating frequency or reduced physical length compared to a single frequency reference dipole. The designed antennas can serve different wireless services for GPS (1.27 GHz and 1.55 GHz), UMTS (1.85 GHz), and WiFi (2.4 GHz) in triple band functionalities. The lower operating frequency antenna size is (70 × 70 mm 2 ) whereas the reduced physical length antenna size is (60 × 70 mm 2 ). At mid band frequencies the reduced frequency antenna length is (0.29 λ 0 , 0.37 λ 0 , and 0.52 λ 0 ), whereas that of the reduced physical length is (0.28 λ 0 , 0.41 λ 0 , and 0.56 λ 0 ), at triple band mid frequency, respectively. Compared to a typical dipole antenna, the designed loaded dipoles can achieve a length reduction that can reach up to 50%. Moreover, the antenna has good gain at the triple bands (−1.2 dB, 1.9 dB and 3.5 dB for reduced operating frequency antenna and −3.1 dB, 1.2 dB and 3.4 dB for the reduced length antenna. The two antennas have good radiation efficiency that can reach up to 84% on a low cost antenna substrate. The mathematical analysis, full wave simulation and experimental measurements of the reported antennas are introduced. [ABSTRACT FROM AUTHOR]

A design of CRLH MIMO metamaterial with reversal CRLH configuration antenna is presented. The two antenna elements are designed to operate at 5.8 GHz for wireless applications. The two antenna elements are designed using reversed one left handed unit cell for high mutual coupling isolation in close separation. The two elements of MIMO antenna are put together with very small separation between them where the distance between the edges of two antenna elements is only 0.034 λ 0 . The MIMO antenna has compact size (its size is only 2.93 × 2.6 cm 2 ). The designed antenna elements have better than 35 dB coupling isolation between the two inputs without using extra structures. The performance of MIMO antennas is evaluated by studying the correlation coefficient, diversity gain and total active reflection coefficient. A good agreement is achieved between simulation and measured results. [ABSTRACT FROM AUTHOR]

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]