ACES Publication Search
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| Title: | ACES Journal August 2024 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1970 KB |
| Title: | ACES Journal August 2024 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 398 KB |
| Title: | ACES Journal August 2024 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 15383 KB |
| Title: | A Miniaturized Pattern-reconfigurable Antenna for Broadband VHF and UHF Communications |
| Abstract: | In this paper, a miniaturized and broadband patter-reconfigurable antenna working at very high frequency (VHF) and ultra-high frequency (UHF) band is proposed. A dipole antenna element with a compact size, stable horizontal gain, a wide bandwidth, and an omnidirectional pattern is introduced firstly, which operates from 116 MHz to 505 MHz with a relative bandwidth of 108.55% and a size of 0.11λL × 0.33λL. An antenna array is constructed by combining four elements in a rotationally symmetrical manner. When one element is excited and other ports are terminated by matched loads, switchable directional beams are achieved. A 10:1 scaled model of the proposed antenna is fabricated and tested. Measured results show that the antenna element operates from 1.48 GHz to 4.86 GHz (a relative bandwidth of 106.62%) with a gain above -2 dBi. The proposed antenna array can achieve directional beams with a high front to back ratio (FBR) with gain value of 3-4 dBi within 2-4 GHz. |
| Author(s): | H. Li, T. Zheng, Y. Mao, Y. Zhou |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1817 KB |
| Title: | An Ultra-wideband Metamaterial Absorber with Angular Stability |
| Abstract: | In this paper, an ultra-wideband (UWB) microwave absorber with robust angular stability is proposed. Each unit of the structure consists of three-layer stacked resistive films to effectively broaden the absorption bandwidth. A metallic via is inserted in the center of the structure, which effectively guides the TM polarization oblique incident wave power to propagate vertically and be absorbed by the resistive films, thus enhancing the angular stability of TM polarization. Within the frequency range of 3.2 GHz to 35.5 GHz, the absorptivity surpasses 90% and the fractional bandwidth reaches 167%. Within an incident angle range of 0° to 60°, the absorptivity of TE polarization remains at about 80%, and the TM polarization can be maintained at over 90%. The absorption mechanism was analyzed by surface power loss and surface current distribution. A sample was fabricated, and the measured results are consistent with the simulated ones. The absorber displays good angular stability and broad bandwidth, making it ideal for electromagnetic stealth applications. |
| Author(s): | R. Xu, X. Ma, X. Kong, S. Zhang, J. Liu, L. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1588 KB |
| Title: | Ultra-wideband Planar Magic-T using Interlayer Coupling 3 dB Directional Coupler and Branch-loaded Phase Shifter |
| Abstract: | In this paper, we propose an ultra-wideband magic-T operating in the frequency band from 1.2 to 4 GHz with a relative bandwidth of 108%, which is based on an interlayer coupling 3 dB directional coupler and a branch-loaded 90° phase shifter. Compared to traditional magic-T structures, it can operate within an ultra-wideband range and has the advantages of a simple structure and easy processing. Simulation and experimental results demonstrate excellent amplitude and phase stability. When the input is at the sum port, the phase error at each output port is less than 2.8°. For the difference port input, the phase error at each output port is less than 7.6°. Furthermore, the overall amplitude imbalance is less than 2.1 dB, the transmission coefficient is below −7.4 dB, and the isolation is greater than 11 dB. It can be used in ultra-wideband phased array systems to generate sum-and-difference beams for direction finding. |
| Author(s): | Y. Shi, D. Chu, Y. Zhou |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1298 KB |
| Title: | High Precision Multiple Parameter Measurement Sensor Based on Constitutive Parameters Near-Zero Media |
| Abstract: | A high-precision multiple parameter measurement sensor based on constitutive parameters nearzero (CPNZ) media has been proposed, which can effectively and accurately predict changes in temperature and relative humidity simultaneously and independently. The dual-channel microwave sensor is composed of a double doping CPNZ substrate integrated waveguide (SIW) cavity, which has the capability to predict different parameters independently. A multi-input and multi-output model is constructed to improve the measurement accuracy by training back propagation (BP) neural network. The relative error of the predicted temperature is smaller than 1.3%, with mean square error (MSE) of ±0.15. The relative error of the predicted relative humidity is smaller than 8.74%, with MSE of ±0.1. The multiple parameter sensor based on CPNZ materials offers a promising platform for multiple parameter sensing research, providing essential technical support and infrastructure for the development of fields like the Internet of Things, intelligent manufacturing, and smart cities. |
| Author(s): | Q. Y. Li, Y. W. Mao, Y. J. Zhou |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1288 KB |
| Title: | QPSK-modulation Wireless Transmitter Based on Time-domain Coding Metasurface |
| Abstract: | In this paper, a wireless communication system based on time-domain digital coding metasurface with Quadrature Phase Shift Keying (QPSK) modulation is proposed. The aperture-coupled resonant rings on the metal patches of the metasurface elements create an asymmetry along the x-axis, resulting in a phase difference. The Field Programmable Gate Array (FPGA) is used to change the conduction and cutoff states of pin diodes, which can control the phase responses of the metasurface elements, forming four coding states. Within a certain period, the FPGA dynamically modulates the high and low levels, thus controlling the reflection characteristics of the metasurface. When the information is converted into a binary bitstream and written into the FPGA, represented by high and low levels, the baseband signal is modulated onto the carrier by the metasurface. This system replaces the functionality of mixers in traditional wireless communication systems, further simplifying the architecture of wireless communication systems. The overall system is demonstrated by an experiment with a picture transmitted and received in real time, showing promise in future low-cost wireless communication transmission systems. |
| Author(s): | J. Wang, J. Li, X. Kong, X. Wang, L. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 11998 KB |
| Title: | Optimization of Multilayer Microwave Absorbers using Multi-strategy Improved Gold Rush Optimizer |
| Abstract: | In this study, a multi-strategy improved gold rush optimizer (MIGRO) is proposed for the design of multilayer broadband microwave absorbers (for normal incidence). The purpose of this optimization process is to minimize the maximum reflection coefficient of the absorber by selecting appropriate material layers from existing literature databases within the desired frequency range. To enhance the performance of a gold rush optimizer (GRO), three improvement strategies are proposed. This paper demonstrates the effectiveness of the improved strategy and the superior reflection coefficient of the MIGRO compared to other heuristic algorithms used for the design of microwave absorbers through two different simulation examples. |
| Author(s): | Y. M. Zong, W. B. Kong, J. P. Li, L. Wang, H. N. Zhang, F. Zhou, Z. Y. Cheng |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 2550 KB |
| Title: | A Nulling Widen and Deepening Algorithm using a Modified Correlation Subtraction Algorithm Multistage Wiener Filtering |
| Abstract: | The calculation of beamforming weights takes time due to the constantly changing direction of interference in highly dynamic environments. The traditional anti-jamming means under static or low dynamic are almost all invalid, so the nulling widen algorithm is studied. However, the commonly used cavitation widening and deepening algorithms are often accompanied by a large amount of computational complexity, which may lead to computational inefficiency and slow processing speed in practical applications. In order to solve this problem, a nulling widen and deepening algorithm using a modified correlation subtraction algorithm multistage Wiener filtering is proposed. The algorithm achieves the deepening after nulling widening by constructing a new covariance matrix, and then reduces the rank by truncating the multilevel Wiener filter at the r-level. It finds the blocking matrix with the normalized reference vectors instead of calculating the blocking matrix directly so that the normalized reference vectors are orthogonal to each other, and finally completes the interference suppression by using the power inversion algorithm to improve the performance and reduce the amount of computation. The computational complexity of the algorithm based on the modified correlation subtraction algorithm multistage Wiener filtering (MCSA-MWF) is O(rM2), which is greatly reduced compared to the computational complexity of the traditional null-spread class algorithm with direct inversion O(M3). |
| Author(s): | X. Li, X. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 5923 KB |
| Title: | Design of a High-frequency Antenna Along a Conducting Surface |
| Abstract: | Antennas in the high-frequency (HF) band (3- 30 MHz) tend to be large and almost always protrude from the structure on which they are mounted. This paper will present a design in which the antenna is installed parallel to and close to a conducting surface. To achieve a small mismatch loss, a thin high-impedance metamaterial surface was designed. The bandwidth is enlarged by applying non-Foster impedances between the ends of the antenna arms and the conducting surface. |
| Author(s): | M. H. Vogel, M. H. Smith |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1123 KB |
| Title: | Effect of Cotton and Wool Fabrics on the Accuracy of Electromagnetic Dosimetry Analysis Due to Millimeter Wave Exposures |
| Abstract: | With the development of wireless communication, satellite, and radar technologies operated at millimeter wave (MMW) frequency range, it is essential to consider the adverse health effects of the radiated electromagnetic (EM) fields at MMW frequency. In most EM dosimetry analyses for the human body models, bare human models have been considered. However, the presence of fabrics such as cotton and wool on the human body can affect the accuracy of the EM dosimetry analysis. At the MMW frequency range, the effect of fabrics on EM dosimetry analysis in a human body model has not been extensively investigated using the finite-difference time-domain (FDTD) method. In this study, the effects of fabrics on the human body on the power transmission coefficient, specific absorption rate, absorbed power density, and heating factor due to EM MMW exposure are investigated using the FDTD method. Numerical results show that the thickness of the fabrics and air gap introduced between the fabrics and the skin surface significantly affects the accuracy of EM dosimetry analysis at the frequency range 1-100 GHz. |
| Author(s): | F. Kaburcuk |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 1024 KB |
| Title: | Safety Assessment of Gender-specific Human Electromagnetic Exposure with Aortic Valve Stents for EV-WPT |
| Abstract: | Electric vehicle wireless power transfer brings additional electromagnetic exposure (EME) risks to the human body, especially those with metal implants. This paper focuses on the safety assessment of human EME with aortic valve stents (AVS), and establishes electromagnetic simulation models for different genders of humans, AVS, and electric vehicle-wireless power transfer (EV-WPT) systems. The transmission power of the EV-WPT system is 11 kW. Considering the uncertainty of the EV-WPT system and AVS in practical use, an efficient deep neural network method is proposed to evaluate the EME safety to different genders of humans. Using the standard limits of the International Committee on Non-Ionizing Radiation Protection (ICNIRP) as the judgment standard, comparing human EME under static conditions, it is demonstrated that AVS can change the distribution of induced electric fields in the human body and increase the risk of human EME. Moreover, the probability of male human EME exceeding the standard limits is 22.78% higher than that of female human. |
| Author(s): | T. Tan, T. Jiang, Y. Wu, Y. Zhu, Y. Chi |
| File Type: | Journal Paper |
| Issue: | Volume: 39 Number: 8 Year: 2024 |
| Download Link: | Click here to download PDF File Size: 16070 KB |