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In this article, a bandwidth-enhanced metasurface has been designed using single circular split ring as unit cell on the top surface of a metal backed FR4 substrate. The structure behaves as cross polarization conversion (CPC) metasurface over full width at half maxima (FWHM) bandwidth of 12.94 GHz ranging from 9.44 GHz to 22.38 GHz. The proposed CPC metasurface maintains bandwidth enhancement upto...
This paper compares congestion controls of Multi-Path TCP (MPTCP) from a view point of Quality of Experience for Web services (Web-QoE) under heterogeneous environment; it assesses Web-QoE by experiments with subjects. The authors treat the four controls (LIA, OLIA, BALIA, WVEGAS) and evaluate Web-QoE by using Web usability. In addition to QoE, they also measure QoS and fairness. Their experiments...
Electrically small Huygens dipole antennas are reported that are low profile, broadside radiating, have high radiation efficiencies, and are either linear (LP) or circularly (CP) polarized. The Huygens behavior, i.e., a high front-to-back ratio with a cardioid-like pattern, is realized by exciting two (LP) or two pairs (CP) of complementary electric and magnetic dipole radiators, simultaneously having...
In this paper, a miniaturized wideband dual-polarized antenna loaded with parasitic loops and straight dipoles has been proposed for 2G/3G/4G base-station applications. Firstly, by loading four parasitic loops to the corners of regular crossed loop dipoles, a miniaturized structure and enhanced impedance bandwidth can be obtained. Then, based on the miniaturized structure, two straight dipoles are...
A compact log periodic antenna (LPDA) is presented in this paper. In this paper, a slotted second iteration of LPDA is demonstrated for size reduction that used for UHF digital TV band application. The proposed antenna operates from 0.5GHz to 1.5GHz for the reflection coefficient ≤ −10dB and maintain the gain of more than 5dBi. The antenna is designed on FR4 Epoxy dielectric substrate with the thickness...
The frequency selective surface (FSS) with ultra-wide passband performance and a sharp rejection near the side of the passband is investigated in this paper. The proposed cascaded FSS consists of a 2-D periodic array of square loop aperture (SLA) and an array of bandstop square loop (SL) with different period. Under different incident waves, the proposed second-order FSS and third-order FSS provide...
The development of left-handed circularly polarized (LHCP) X-band printed antenna for microsatellite data communication is presented. The antenna which takes a circular shape with ellipse-shaped truncation is designed to resonate at the frequency of 8.2GHz with the minimum axial ratio bandwidth of 400MHz. The proposed antenna is deployed on a 1.6mm thick NPC-H220A dielectric substrate. The realized...
This paper presents a slotted-rectangular patch antenna with proximity-coupled feed operated at dual band of millimeter-wave (mmV) frequencies, 28GHz and 38GHz. The antenna was built in multilayer substrate construct by 10-layers Low temperature Co-fiber Ceramic (LTCC) with 5 mils thickness each. The slotted-patch and thick substrate are configured to enhance the bandwidth and obtain a good result...
This paper presents the development of dual-band patch antenna incorporated with split ring resonator (SRR) for Global Positioning System (GPS) and Wireless Local Area Network (WLAN) application. The antenna is composed of 3 layers of copper conductor flanking 2 layers of FR4 Epoxy dielectric substrate with the total thickness of 1.6mm and the dimension of 78.6mm × 48.4mm. The characterization shows...
We have proposed an open terminated folded inverted-L antenna (FILA) with slits. In order to miniaturize the FILA, several slits are employed on the substrate surface. Folded structure is used for broadbanding. Design of the FILA to achieve broadband characteristics is shown. Simulation and measurement are implemented, and comparison of the results are evaluated. Finally, we calculate the product...
In this paper, the size of a log-periodic dipole array antenna is reduced using partially applied folded planar helix dipole elements. The proposed antenna shows almost no gain deterioration in the entire operating bandwidth even though its size is reduced by 39 %. Due to its reduced size and lightweight characteristics, it is expected that the proposed antenna could be effectively utilized in the...
Recently, applying the multimedia wireless sensor networks and computer vision techniques in the outdoor agriculture field can be observed. Since the performance of such techniques is limited by the low data rate of the wireless sensor network, the transmission using the wider bandwidth is one of the possible solutions. This paper proposes the technique to develop the wide-band channel sounder for...
We report the intermediate results on a novel slotted waveguide antenna for point-to-point communications at Ka band. The antenna adopts an aperiodic layout with uniformly-excited elements capable of meeting the ETSI class II radiation pattern envelop in all planes with high aperture efficiency. A total of 16 regular waveguide subarrays with an aperiodic inter-column spacing along the E-plane are...
Now a day's increasing demand for higher bandwidth and other benefits of millimeter waves like line of sight communication and non bending property, molecular absorption, higher antenna gain at high frequencies make millimeter wave component design a favorite area of working. This transition structure of waveguide to microstrip line is useful for integration of high frequency circuits to the waveguide...
With compact folded method, a kind of folded crossed dipole ultra wideband antenna is proposed with omnidirectional radiation characteristics on the horizontal direction in this paper. The antenna is comprised of orthogonal crossed semicircular metal discs with twice 90° folded on both ends. Horizontal size is reduced obviously compared with original crossed semicircular disc antenna. This antenna...
Scattering performance of a reflectarray using a log-periodic dipole array (LPDA) element is demonstrated numerically and experimentally. The LPDA element and the reflectarray are designed using method of moments (MoM). The designed 10 × 1 reflectarray was fabricated using a 3D printing technology. A bistatic radar cross section (BRCS) of the designed reflectarray was measured in a radio anechoic...
In the 5G system, high frequency bands over 6 GHz (6–100 GHz) will be a key factor in providing a very wide bandwidth. Because of high path losses, these bands are considered to use for small cells. To design radio links with high accuracy and evaluate 5G system performances for various scenarios, channel characteristics must be clarified. In this paper, we clarify channel characteristics in an outdoor...
Reducing operation and the maintenance costs of wind turbines has become a primary issue of wind farm owners and operators. Since the supervisory control and data acquisition (SCADA) system has been widely used in wind farms, it is costeffective to use SCADA data to realize condition monitoring. To this end, this paper proposes a method to calculate health index of wind turbines based on SCADA data...
A 4.6–5.6 GHz constant KVCO LC-VCO applied in PLL frequency synthesizer is presented in this paper. With constant KVCO LC-VCO and programmable charge pump, the frequency synthesizer is able to obtain constant bandwidth. Furthermore, the VCO has a low KVCO which will result low phase noise. An Optimized automatic frequency calibrator (AFC) is proposed, the AFC can select the sub-band which is nearest...
A novel discrete sinusoidal signal integrator (DSSI) structure is proposed in this paper for single grid-tied inverters. The DSSI provides an adjustable gain and bandwidth at the expected frequency and a highly attenuated gain at other frequencies which make the DSSI based controllers obtain the zero steady-state error tracking performance of arbitrary frequencies. The performance of the conventional...
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