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Showing papers in "Microwave and Optical Technology Letters in 2017"




Journal ArticleDOI
TL;DR: This article presents a compact size asymmetric CPW strip-fed UWB two-element MIMO antenna, with notched-band behavior, designed, simulated, fabricated, and tested to show the antenna suitability for MIMo systems.
Abstract: This article presents a compact size asymmetric CPW strip-fed UWB two-element MIMO antenna, with notched-band behavior. The single-antenna element of the MIMO configuration is composed of a semi-elliptical patch radiator with asymmetric ground plane. The notched-band behavior of the proposed antenna is achieved by inserting a simple folded stub to the patch radiator. This stub achieves the desired single stop-band from 3.3 to 3.9 GHz for WIMAX. The two-antenna elements are placed orthogonally to achieve pattern diversity which leads to an improved MIMO system performance and enhances the isolation between elements without using any decoupling structures. The antenna has dimensions of 50 3 28 mm. The edge-to-edge distance between antenna elements is 0.15k0 at 3 GHz. The proposed antenna is designed, simulated, fabricated, and tested. Results show that the two-antenna elements operate at frequencies ranging from 2.8 to 11.5 GHz with return loss lower than 210 dB and insertion loss lower than 218 dB. The performance of the MIMO antenna diversity characteristics were verified through the calculation of the standard parameters and show the antenna suitability for MIMO systems. VC 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1460–1464, 2017; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.30564

58 citations




Journal ArticleDOI
TL;DR: In this article, a fully printed CPW-fed antenna based on silver-nanoparticles for ISM that is flexible, wearable, and reversibly deformable was demonstrated. And the proposed antenna consists of nano-silver ink, a conducting material used as a radiating patch and ground planes printed on the polyethylene terephthalate flexible substrate.
Abstract: This article demonstrated a fully printed CPW-fed antenna based on silver-nanoparticles for ISM that is flexible, wearable, and reversibly deformable. The proposed antenna consists of nano-silver ink, a conducting material used as a radiating patch and ground planes printed on the polyethylene terephthalate flexible substrate. The fully printed antenna was fabricated and the radiating properties were investigated. The simulated and measured reflection coefficients are ∼−31 dB and ∼−23 dB, respectively. Meanwhile, the −10 dB bandwidth is ∼530 MHz and the obtained VSWR is ∼1.3. Radiating properties were characterized and agree well with the simulation results. The material and fabrication technique illustrated here could be extended to achieve other types of flexible antenna with more complex patterns for wearable electronics applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:204–208, 2017

47 citations


Journal ArticleDOI
TL;DR: In this paper, a novel compact unilayer frequency selective surface (FSS) for UWB applications was proposed, which consists of simple metallic patterns printed on both sides of 14 mm × 14 mm FR4 substrate.
Abstract: This paper presents a novel compact unilayer frequency selective surface (FSS) for ultra-wideband (UWB) applications particularly for gain enhancement of printed antennas. The proposed FSS unit cell consists of simple metallic patterns printed on both sides of 14 mm × 14 mm FR4 substrate. The proposed FSS has very low transmission co-efficient and linearly decreasing reflection phase over the bandwidth of 9 GHz in 3–12 GHz range, which makes it suitable candidate to provide in-phase reflection for UWB antennas. For the validation of gain-enhancement capability, the FSS is paired with a general monopole UWB antenna demonstrating an average gain improvement of 4 dB. The antenna composite has a maximum gain of 8.9 dBi.

47 citations


Journal ArticleDOI
TL;DR: The proposed approach is validated in a laboratory‐controlled environment by considering experimental measurements for both training and testing SVM phases and proves that a very high detection accuracy can be yielded even though using a limited amount of training data.
Abstract: The real‐time detection of brain strokes is addressed within the Learning‐by‐Examples (LBE) framework. Starting from scattering measurements at microwave regime, a support vector machine (SVM) is exploited to build a robust decision function able to infer in real‐time whether a stroke is present or not in the patient head. The proposed approach is validated in a laboratory‐controlled environment by considering experimental measurements for both training and testing SVM phases. The obtained results prove that a very high detection accuracy can be yielded even though using a limited amount of training data.

45 citations


Journal ArticleDOI
TL;DR: In this article, a lightweight, rapidly-manufactured X-band waveguide horn antenna, made by 3D printing and conductive spray coating, is proposed, which has the advantages of being low-cost and lightweight and can be rapidly manufactured with an easy construction process.
Abstract: Herein, a lightweight, rapidly-manufactured X-band waveguide horn antenna, made by 3D printing and conductive spray coating, is proposed. The proposed antenna has the advantages of being low-cost and lightweight and can be rapidly manufactured with an easy construction process. To metalize the inside of the horn antenna, the antenna CAD model is split into four pieces. The four assembly parts are 3-D printed with polylactic acid (PLA) using the fused deposition modeling (FDM) method. After 3D printing, each part is metalized via conductive spray coating. Last, the sprayed parts are assembled using polycarbonate bolts and nuts. Experimental results show that the antenna weight is only 19.3% of a commercial computerized numerically controlled (CNC) machined metallic antenna. To verify the antenna performance, the reflection coefficient and gain characteristics of the proposed 3D printing horn antenna are compared with those of an aluminum horn antenna of the same size. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:727–729, 2017

43 citations




Journal ArticleDOI
TL;DR: In this article, a compact UWB-MIMO antenna with WLAN band notched characteristic is presented, where two closely spaced planar-monopole elements on the top side of the dielectric substrate with a truncated ground-plane etched on the bottom side.
Abstract: A compact UWB–MIMO antenna with WLAN band notched characteristic is presented. UWB coverage is achieved with two closely spaced planar–monopole elements on the top side of the dielectric substrate with a truncated ground‐plane etched on the bottom side. Isolation between the antennas is achieved by creating a current path to decouple energy between the radiation elements using a T‐shaped ground stub. Notched frequency band between 5.15 and 5.85 GHz is achieved with a parasitic rectangular strip on the bottom side, which is connected to the radiating patch through a via hole. This approach yields a highly compact antenna design having dimensions of 22 × 29 × 0.8 mm3. Simulated and measured results confirm the antenna has an impedance bandwidth of 7.6 GHz from 3.0 to 10.6 GHz making it suitable for UWB MIMO systems.

Journal ArticleDOI
TL;DR: In this article, a compact asymmetric coplanar strip-fed UWB MIMO antenna was proposed for portable UWB applications, where the antenna elements have less than 15 dB coupling isolation between the two input ports.
Abstract: This article presents a new compact asymmetric coplanar strip -fed UWB MIMO antenna. The UWB MIMO antenna consists of two identical elements which have quarter elliptical ring radiating element with asymmetric coplanar strip-fed. By designing the antenna using asymmetric coplanar strip-fed, the antenna size can be reduced (its size is only 6 × 2.6 cm2). The distance between the two antenna elements equals 0.37 λ0-The single antenna element is operated at frequencies from 3.1 GHz to 10.6 GHz with reflection coefficient lower than −10 dB. In addition, the designed antenna elements have less than 15 dB coupling isolation between the two input ports. The diversity performance between two antenna elements such as envelope correlation coefficient and diversity gain are investigated and they are within their allowed limits. This analysis confirms that the designed antenna is suitable for portable UWB MIMO applications. The proposed antenna is designed; simulated and measured. There is a good agreement between the simulated and measured results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:31–36, 2017






Journal ArticleDOI
TL;DR: In this paper, the design and implementation of a compact bowtie antenna with a 3D printed substrate and coplanar stripline feed structure is described. And the proposed method provides a cost-effective manufacturing method with good performance.
Abstract: This article describes the design and implementation of a compact bowtie antenna with a three-dimensional (3D) printed substrate and coplanar stripline feed structure. The electrical properties of the 3D printed substrate were measured using a Keysight high performance dielectric probe. The proposed bowtie antenna was designed, simulated, and fabricated at the center frequency of 2.6 GHz. The proposed method provides a cost-effective manufacturing method with good performance. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:706–710, 2017




Journal ArticleDOI
TL;DR: In this paper, a new type of wearable aperture-coupled patch antenna for 2.4 GHz wireless body area network (WBAN) application is proposed, and the H-shaped slot in middle ground plane and rectangular ring microstrip feed line are optimized, so that it realizes the efficient electromagnetic coupling with the radiating element.
Abstract: A new type of the wearable aperture-coupled patch antenna for 2.4 GHz wireless body area network (WBAN) application is proposed. The H-shaped slot in middle ground plane and rectangular ring microstrip feed line are optimized, so that it realizes the efficient electromagnetic coupling with the radiating element. The substrate layers are 2 mm thickness felt layers with relative permittivity of 1.2, and the other layers are copper foil tape (CFT) to ensure the performance of the antenna. Furthermore, the return loss, radiation pattern and gain are investigated in detail for the antenna under different bending curvature radius. Experimental results show a good agreement with simulation results. (C) 2017 Wiley Periodicals, Inc.

Journal ArticleDOI
Guoping Gao, Bin Hu, Lele He, Shaofei Wang, Chen Yang 
TL;DR: In this paper, an ultra-wideband (UWB) antenna with reconfigurable performance is proposed, which consists of a Ushaped radiation patch and a ground plane which is symmetric with the edge of the radiation patch.
Abstract: In this paper, an ultra-wideband (UWB) antenna with reconfigurable performance is proposed. The antenna consists of a Ushaped radiation patch and a ground plane which is symmetric with the edge of the radiation patch. By using two open-ended L-shaped slots (OEL-S) and one U-shaped slot Defected Ground Structure, the dual notched bands at 3.5 GHz for WiMAX and 5.5 GHz for WLAN are obtained. Three switches are embedded in both L-shaped and U-shaped slots in order to achieve four switchable modes by switching them between ON and OFF states. There are three modes that the antenna can be switched in, which are dual, single and no band-notched modes. The measured result illustrates that the operation frequency band is from 2.7 GHz to 12 GHz ( VSWR<2). Moreover, the conceptual circuit model and time-domain characteristics of the antenna are also proposed to investigate the dual band-notched performance. (C) 2017 Wiley Periodicals, Inc.



Journal ArticleDOI
TL;DR: In this paper, a cavity-backed antenna with multi-resonance slots for Ku-band application is presented and experimentally investigated in terms of antenna performances including S-parameter, optimized parameter values, gain, and radiation pattern.
Abstract: In this article, a wideband substrate integrated waveguide (SIW) cavity-backed antenna with multi-resonance slots for Ku−band application is presented and experimentally investigated in terms of antenna performances including S-parameter, optimized parameter values, gain, and radiation pattern. With the proper placement of multi-resonant slots on the backside of the cavity, the hybrid modes are generate in the frequency band of interest. These modes can be tuned by varying the slot parameters which result the merging of different resonant frequencies, therefore the simulated impedance bandwidth is substantially enhanced to 1.46 GHz, ranging from 12.7 to 14.16 GHz with a gain of 6.0 to 8.0 dBi. The measured result showing the fractional bandwidth of the proposed antenna is 11.8% and 11% achieved at the resonant frequencies of 13 and 14 GHz, respectively. Moreover, the antenna has the features of simple-single layer structure, resonant frequency flexibility with multi-resonance characteristics over a wide impedance bandwidth.



Journal ArticleDOI
TL;DR: In this article, a microstrip diplexer is implemented based on a novel combination of the coupled lines and spiral structures in order to reduce the circuit size as well as insertion losses.
Abstract: In this article, a microstrip diplexer is implemented based on a novel combination of the coupled lines and spiral structures in order to reduce the circuit size as well as insertion losses This diplexer with an elliptic function frequency response operates at 24/279 GHz for wireless applications Several transmission zeros on the both sides of two passbands are realized, which improve the selectivity A theory method is presented that helps to miniaturization, control the resonance frequency, improve the insertion loss, and external quality factor simultaneously The proposed diplexer has a compact size of 03λg × 025λg with low insertion losses of 018/039 dB at 24/279 GHz The isolation between the two channels (S23) is better than 205 dB from DC up to 6 GHz The designed diplexer is fabricated and measured There is a good agreement between the simulated and measured results