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The proposed butterfly-shaped monopole ultra-wideband (UWB) antenna consists of two radiating elements (wings) positioned with an angle between them, which provides one more dimension for impedance matching. The simulated and measured results show that the design achieves a broad impedance bandwidth and stable radiation performance over the UWB band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 590–593, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24125 [ABSTRACT FROM AUTHOR]

This article proposes a position detection method for a multi-to-one wireless power transmission (WPT) system for the first time and applies it to the position detection of a spherical motor. The traditional contact detection system has high friction resistance and poor rotor positioning accuracy. Although some noncontact measurement systems are not directly connected to the rotor, the structure or calculation of the measurement system is more complicated. To solve the abovementioned problems, this article proposes two structural topologies, which are evenly arranged on the upper part of the rotor and the receiving coil is placed on the rotor shaft. When the motor rotor rotates along with the three motion states of yaw, spin, and tilt, the receiving and multitransmitting coils will have an angular offset. The rotor position is obtained by a method of accurately estimating the mutual inductance. This method avoids complicated finite element calculations and saves a lot of time. Finally, the experiment verifies the above analysis and compares the data with the microelectromechanical system three-degree-of-freedom attitude detection method. This article provides insights into the position detection of spherical motors. This method simplifies the previous measurement system and obtains higher positioning accuracy. [ABSTRACT FROM AUTHOR]

Although surface-wave plasma (SWP) sources have many industrial applications, the ionization process for SWP discharges is not yet well understood. The resonant excitation of surface plasmon polaritons (SPPs) has recently been proposed to produce SWP efficiently, and this work presents a numerical study of the mechanism to produce SWP sources. Specifically, SWP resonantly excited by SPPs at low pressure (0.25 Torr) are modeled using a two-dimensional in the working space and three-dimensional in the velocity space particle-in-cell with the Monte Carlo collision method. Simulation results are sampled at different time steps, in which the detailed information about the distribution of electrons and electromagnetic fields is obtained. Results show that the mode conversion between surface waves of SPPs and electron plasma waves (EPWs) occurs efficiently at the location where the plasma density is higher than 3.57 × 1017 m-3. Due to the effect of the locally enhanced electric field of SPPs, the mode conversion between the surface waves of SPPs and EPWs is very strong, which plays a significant role in efficiently heating SWP to the overdense state. [ABSTRACT FROM AUTHOR]

This article proposes a rotor attitude estimation (RAE) method for spherical motors using the multiobject Kalman kernel correlation filter (MKKCF) algorithm in monocular vision. A permanent magnet spherical motor (PMSpM) is adopted as the research object, and a monocular area scan camera is equipped in the RAE system with a visual feature component mounted on top of the rotor output shaft. In the proposed MKKCF algorithm, the Kalman filter is used to enhance the robustness and accuracy of KCF tracker for each object. To simplify the proposed algorithm verification, a one-object tracking comparison is conducted among the KCF algorithm, the fast discriminative scale space tracking (FDSST) algorithm, and the Kalman KCF algorithm, and the results show that Kalman KCF tracker is more applicable for RAE. In addition, an RAE test bench is developed, and the MKKCF-based RAE method and the micro-electro-mechanical system (MEMS) (MPU9250) method are compared when estimating the rotor attitude. To set a benchmark, the contact rotor position measurement with encoders is used. The comparison results indicate that the MKKCF-based RAE method works with higher accuracy than the MEMS method. Finally, a closed-loop PMSpM control experiment is conducted by using the proposed MKKCF-based RAE method, and the practicability of the proposed method is proved. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high-gain circularly polarized magnetoelectric dipole antenna array for millimeter-wave is proposed. • An antenna array design method of trade-off between high gain and low profile is proposed in this paper. • The 4 × 4 antenna array achieves 20.4 dBic peak right-handed circularly polarized gain. A high-gain circularly polarized (CP) magnetoelectric (ME) dipole antenna with metallic radiating structure is presented. The proposed CP antenna element consists of two pairs of metallic posts with a supporting metallic plate, a metallic air-filled elliptical cavity, and a feeding slot on the bottom substrate integrated waveguide (SIW). The two pairs of modified rectangular metallic posts combined with the gaps between them act as radiating ME-dipoles which are surrounded by a metallic air-filled elliptical cavity. The above-mentioned radiating structures are fed by a modified cross-shaped coupling slot etched on the bottom feeding SIW to generate CP radiation, where loading the elliptical metallic cavity significantly improve the CP performance of the antenna element. Then, a 4 × 4 antenna array with full-corporate feeding network is designed, fabricated, and measured, which has an impedance bandwidth of 18.9 % from 37.4 to 45.2 GHz and a 3-dB axial ratio (AR) bandwidth of 14.2 % from 36 to 41.5 GHz. Thanks to the all-metal radiating structures, a maximum measured gain of 20.4 dBic has been achieved. The measured and simulated results are in good agreement. [ABSTRACT FROM AUTHOR]

A permanent magnet spherical motor (PMSpM) is a representative multiple degree-of-freedom electric apparatus. This paper proposes new analytical models for the PMSpM with stepped cylindrical permanent magnets (PMs). The research is not only to obtain the magnetic field and torque models of the PMSpM but also to yield a potential analytic tool for the spatial magnetic field and torque decomposition. The model decomposition aims to acquire a potential tool for the future research on PMSpM topology optimization and working mechanism. To achieve the two research targets above, the toroidal expansion method is used for magnetic field modeling, and the finite element method verification and experimental verification are conducted. Then, forces and torques are deduced from the Lorentz force law. In addition, a prototype PMSpM has been produced and the comparison studies of the air-gap flux density and torque among decomposed components are conducted using finite element analysis results and experimental results. It is concluded that the proposed analytical PMSpM models and the model decomposition method are proved. [ABSTRACT FROM AUTHOR]

A high‐gain, low‐cost empty substrate integrated waveguide (ESIW)‐fed circularly polarized (CP) antenna array is demonstrated for millimetre‐wave 5G applications in this letter. The ESIW is formed by metallized FR4 printed circuit boards. By stacking the metallic aluminium z‐shaped radiating slots atop the ESIW feeding network, CP radiation is achieved. The proposed 1 × 8 antenna array offers a high measured gain of 17.8 dBic and high measured radiation efficiency of 89.1%. The measured impedance bandwidth for |S11| ≤ −10 dB and measured axial ratio (AR) bandwidth for AR ≤ 3 of the proposed 1 × 8 array are 11.4% (36.5–40.9 GHz) and 7.8% (37–40 GHz), respectively. [ABSTRACT FROM AUTHOR]

Deep learning (DL) technology is an effective tool for automatic modulation recognition (AMR) in the field of cognitive radio (CR). Most of the existing DL-based approaches usually design a deep network with many layers, in which only refined features from the final layer are used for AMR. However, rough features from other layers (i.e., features captured in a shallow network with fewer layers) can also provide useful information for modulation recognition. These rough features are not carefully exploited in previous approaches. In this paper, we propose a novel multi-path features fusion network for AMR, in which both refined and rough features are learned. The proposed approach identifies 11 signals including digital modulation and analog modulation generated by the GNU radio and compared to the classic network in all SNR. The experiment results show that the effectiveness of our approach. Especially, our approach is able to achieve 99.04% accuracy in +18dB SNR which outperforms all comparison approaches. [ABSTRACT FROM AUTHOR]

ABSTRACT A compact coplanar waveguide fed circular wide-slot antenna with dual-band-notched characteristic is proposed by using an arc-shaped slot (ASS) and an arc-shaped parasitic element (ASPE) for ultra-wideband (UWB) communication applications. The center frequencies of the dual-notch bands can be tuned in a wide range by adjusting the parameters of the ASS and the ASPE. Both the numerical and experimental results show that the proposed antenna can operate over a wide frequency band ranging from 2.7 to 12 GHz with VSWR < 2, with the exception of the two notch bands operating at wireless local area network band and X-band. In addition, the proposed antenna has a compact size and omnidirectional radiation pattern, which is suitable for UWB communication applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1240-1244, 2014 [ABSTRACT FROM AUTHOR]

In this article, we propose a circular slot ultrawideband (UWB) antenna with multimode reconfigurable dual band-notched characteristics. By using a two-stage T-shaped stepped impedance resonator (TS-TSIR) and a parallel stubs loaded resonator (PSLR), dual band-notched function is achieved to reject worldwide interoperability for microwave access, WLAN, and X-band signals. The multimode reconfigurable band-notched characteristic is realized by integrating four switches onto the TS-TSIR and the PSLR. Simulated and measured results show that this antenna, with multimode reconfigurable characteristics and dual band-notched function, can operate from 2.7 to 12 GHz (VSWR<2), which includes the entire UWB band. This antenna maintains omnidirectional radiation patterns that is suitable for UWB applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:570-574, 2014 [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a wide-slot ultrawideband antenna with dual band-notch characteristics is proposed numerically and verified experimentally. The dual band-notch functions are obtained by using a nested split ring resonator (NSRR) and a stepped impedance resonator (SIR). The designed two notch bands are tunable by adjusting the dimension of the NSRR and the SIR. Simulation and measurement results agree well. The proposed antenna with omnidirectional radiation patterns and desired notch bands is suitable for UWB communication applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2827-2830, 2013 [ABSTRACT FROM AUTHOR]

ABSTRACT An asymmetric coplanar strip (ACS)-fed dual-band antenna using loaded capacitance terminations for 2.4/5.8 GHz wireless local area network applications is studied numerically and verified experimentally. The proposed antenna consists of two meandered strip radiating elements, two loaded capacitance terminations, an asymmetric ground plane, a shunt inductor, and an ACS-fed structure. Two resonance frequencies are controlled by adjusting the dimensions of the two meandered strip radiator elements and two loaded capacitance terminations. This antenna has small size of 17 × 12 mm2 including the ground plane. Simulation and measurement results show that the proposed antenna can work at dual-band frequencies and has omnidirectional radiation patterns. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2066-2070, 2013 [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel approach to address the challenge posed by large datasets in the context of antenna optimization through machine learning (ML). The approach involves a modified artificial neural network (ANN) technique. To tackle the issue of training with limited data, we introduce a method that leverages prior knowledge to create initial small datasets. Throughout the training process, these datasets are iteratively enhanced by incorporating new simulation data obtained from optimization results. In the applications presented here, ANN is used to establish a relationship model between antenna geometric variables and transmission coefficients (S 21). Subsequently, a genetic algorithm (GA) is used to optimize the decoupling of the antenna array. By implementing wideband and narrowband optimization of the S 21 between two antennas, the accuracy and efficiency of this method are verified. The initial design and optimized antennas were fabricated and measured. In summary, this proposed method not only can effectively mitigate the expenses associated with design but also generates antenna optimization solutions of high quality. [ABSTRACT FROM AUTHOR]

This paper presents a circularly polarized (CP) slot antenna array using substrate integrated waveguide (SIW)–feeding network at Q-band. To achieve CP radiation and high-gain performance simultaneously, a metallic radiating slanted cross slot is stacked atop an SIW coupling slot in the CP antenna element design. The fabricated CP antenna element features 14.6% (42.6–49.3 GHz) measured impedance bandwidth for |S11| ≤ −10 dB, 9.1% (42–46 GHz) measured 3-dB axial ratio (AR) bandwidth for AR ≤ 3, and 8.3 dBic measured peak gain, respectively. Then, a 1 × 8 antenna array is designed, fabricated, and measured. The measured results demonstrated that the impedance bandwidth and 3-dB AR bandwidth of the proposed 1 × 8 array are 14.8% (41.9–48.6 GHz) and 11% (43–48 GHz), respectively. The measured peak gain of the 1 × 8 array is 14.7 dBic at 44 GHz. [ABSTRACT FROM AUTHOR]

This paper proposes a monolayer Halbach array based permanent magnet spherical motor (PMSpM) using cubic permanent magnets (PM). The research aims to provide a fast computing model to calculate the magnetic field for this PMSpM, which helps for future PMSpM optimization and control study. Three thickness equivalence principles are provided and compared for cubic PMs. The magnetic scalar potential is introduced, and the spherical harmonics expansion is implemented for rotor magnetic field analysis. Engineering revision is used to reduce the Legendre function deviation in polar angle direction. Torques and forces are deduced using the Lorentz force law, and relatively simple models of this PMSpM for both magnetic fields and torques are acquired. In addition, a prototype motor has been developed, and the analytic results of air-gap flux density and torque are compared with their finite element simulation and experimental results, which are proved consistent. It is concluded that the fundamental component of the spherical harmonics can be used to present the magnetic field model, which uses fewer integrals than the Biot-Savart law based solution, and the modeling results of the magnetic field flux density, forces and torques are in line with the expectations. The analytic models are proved correct. [ABSTRACT FROM AUTHOR]

A compact asymmetric coplanar strip-fed staircase ultrawideband (UWB) antenna with notch band reconfigurable characteristic is proposed and investigated numerically and experimentally.The reconfigurable notch bands are realized by using a spur-slot and an ideal switch. By controlling the switch at OFF and ON states, the notch bands of the proposed UWB antenna can work at 3.5 and 8.2 GHz, respectively. Numerical and experimental results show that the proposed antenna is capable of working for entire UWB application and providing the reconfigurable notch bands. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1467-1470, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27634 [ABSTRACT FROM AUTHOR]

A reconfigurable wide slot antenna integrated with stepped impedance resonators (SIRs) and ideal switches for ultra-wideband (UWB) and multiband communication applications is proposed. The proposed reconfigurable antenna can be used as a UWB antenna, a dual notch-band UWB antenna, and multiband antennas. The dual notch-band functions are obtained by using two stepped impedance stub-loaded SIRs. The reconfigurable characteristics are achieved by using two ideal switches on SIRs. The measurement and simulation results show that the proposed reconfigurable antenna has good switchable characteristics and dual notch-band functions. The designed reconfigurable antenna is suitable for future multimode wireless communications systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:52-55, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27253 [ABSTRACT FROM AUTHOR]

It is difficult to realize a traveling wavemode current on a single conductor loop to generate a wideband circularly polarized (CP) radiation wave using a single feeding structure. In this communication, with the help of the characteristic mode analysis, we cut a wide gap in the annular ring conductor patch and design the feeding structure with capacitive coupling effect on the patch. By this way, the annular patch is effectively distributed with traveling wave currents and a printed annular ring antenna operating in the 2.4 GHz band is constructed. The experimental results show that the proposed antenna can generate CP radiation with impedance and axial ratio bandwidths of 26% and 10.6%, respectively. Meanwhile, this antenna has a good structural tolerance capability. [ABSTRACT FROM AUTHOR]

An energy efficient protocol for routing and scheduling in wireless body area networks is proposed by considering node energy, path loss, traffic type, and other relevant factors. First, a channel competition procedure is proposed to reduce network flooding, making use of the related information that sensor nodes collected in the initialization phase. Then, energy abundant routes are selected according to the node type and energy consumption in routing setup phase. Finally, an adaptive slot assignment method is designed to meet requirements of data rate and priority in slot assignment phase. The simulation results show that the proposed protocol not only save energy, but also improve the channel utilization. [ABSTRACT FROM AUTHOR]

This paper deals with the hybrid particle swarm optimization-Cuckoo Search (PSO-CS) algorithm which is capable of solving complicated nonlinear optimization problems. It combines the iterative scheme of the particle swarm optimization (PSO) algorithm and the searching strategy of the Cuckoo Search (CS) algorithm. Details of the PSO-CS algorithm are introduced; furthermore its effectiveness is validated by several mathematical test functions. It is shown that Lévy flight significantly influences the algorithm's convergence process. In the second part of this paper, the proposed PSO-CS algorithm is applied to two different engineering problems. The first application is nonlinear parameter identification for the motor drive servo system. As a result, a precise nonlinear Hammerstein model is obtained. The second one is reactive power optimization for power systems, where the total loss of the researched IEEE 14-bus system is minimized using PSO-CS approach. Simulation and experimental results demonstrate that the hybrid optimal algorithm is capable of handling nonlinear optimization problems with multiconstraints and local optimal with better performance than PSO and CS algorithms. [ABSTRACT FROM AUTHOR]

Integration of distributed generation (DG) at large scale with high penetration challenges the radial structure of the traditional distribution networks and the effectiveness of the conventional voltage regulation methods. In this study, the clusters partitioning and voltage regulation are researched. The modified electrical distance is introduced. An effective method, based on spectral clustering algorithm, is proposed for the partitioning of the DG network via the judgement of critical load buses. Two‐stage voltage regulation optimisation is realised in each sub‐community. The optimal objects are the minimal voltage fluctuation and the network loss of the distributed network. The independent variables are reactive‐power absorption and active‐power curtailment for each controllable photovoltaic node. An advanced particle swarm optimisation algorithm is applied to the voltage regulation for the sub‐communities. After a case study of the IEEE 33‐bus system, a regional distribution network in Anhui province of China is analysed. Simulation results indicate that the node voltages are stabilised with the improvement of power quality employing the proposed clusters partitioning method and zonal power control scheme. [ABSTRACT FROM AUTHOR]

The measurement system of contact spherical actuator has the disadvantages of large friction resistance and poor rotor positioning accuracy. The structure or calculation of non-contact attitude measurement system is complicated. In order to solve the above problems, a multi-to-one wireless power transmission (WPT) spherical actuator attitude measurement method is proposed. The model of mutual inductance(MI) is built. This method effectively shortens the time of finite element analysis(FEA). Three motion states (spin, yaw and tilt) of actuator rotor are analyzed by using this measurement method. Compared with the micro electro mechanical system (MEMS) and fast complementary filter (FCF), the initial attitude error of this method is about 50% of that of the other two methods. Compared with MEMS method, the average angle error of WPT method is reduced by 35%. Experimental results show that this method has good real-time performance and repeatability. [ABSTRACT FROM AUTHOR]

In this paper, 30-mm-wide cold atmospheric-pressure air plasma brushes are reported. The brushes driven by a direct current power supply are capable of generating air plasma glows with no noble gas addition and no airflow supplement. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform no matter what kinds of material are being processed. The air plasma glow can be scaled up by using the plasma brush arrays. About 30\ \mm \times 30\ \mm \times 5\ \mm ( W, H, and L) homogeneous air plasma glow is generated by merging seven-brush arrays. Current measurements show that the single-brush discharge appears periodically pulsed, while the brush array discharge actually presents either pulsed with about array-number-times frequency of the single one. A further analysis indicates that the charge particles trapped along the dielectric surface may be responsible for the discharges. [ABSTRACT FROM PUBLISHER]