Yiwei Chen, Yang Yang, Xiaoxiang He, Xiaohui Yu, Wenwu Zhang
This study introduces a novel phase compensation-based, asymmetric frequency selective surface (FSS). Aimed at enhancing angular stability, the phase compensation method utilizes the reflected phase gradient changes generated by two FSSs at large grazing angles. The ultimate improvement in angular stability comes from unit amalgamation to achieve phase complementarity, effectively dealing with the phase shift of incident waves caused by large grazing angles. Based on this principle, the asymmetric FSS structure is built with 3 components: a Minkowski fractal cell, a bent-line square-loop cell, and a thin square-loop parasitic cell. Simulation results show the structure demonstrates a 0 relative shift of resonant frequency within an incidence range of 0-80° under transverse electric (TE) polarization. However, it exhibits a maximum relative shift of 5.12% in resonant frequency at an 80° incidence under transverse magnetic (TM) polarization. Compared with E 1 and E 2 units, this structure significantly reduces frequency deviation—by 100% at 80° incidence under TE polarization and by 80.12% and 83.26% compared with E 1 and E 2 units under TM polarization. Finally, the proposed FSS model was fabricated and processed, with measured data basically aligning with the simulated results.
本研究介绍了一种基于相位补偿的新型非对称频率选择表面（FSS）。为了增强角度稳定性，相位补偿方法利用了两个 FSS 在大掠角下产生的反射相位梯度变化。角度稳定性的最终改善来自于通过单元合并来实现相位互补，从而有效地处理大掠射角引起的入射波相移。根据这一原理，非对称 FSS 结构由三个部分组成：闵科夫斯基分形单元、弯曲线方环单元和薄方环寄生单元。仿真结果表明，在横向电（TE）极化条件下，该结构在 0-80° 入射角范围内的谐振频率相对偏移为 0。然而，在横向磁（TM）极化条件下，其谐振频率在 80° 入射角范围内的最大相对偏移为 5.12%。与 E 1 和 E 2 单元相比，该结构大大减少了频率偏差，在 TE 极化条件下，入射角为 80°时，频率偏差减少了 100%；在 TM 极化条件下，与 E 1 和 E 2 单元相比，频率偏差分别减少了 80.12% 和 83.26%。最后，对提出的 FSS 模型进行了制作和处理，测量数据与模拟结果基本一致。
{"title":"Angular Stability Enhancement Using Phase Compensation Method for Frequency Selective Surface Design","authors":"Yiwei Chen, Yang Yang, Xiaoxiang He, Xiaohui Yu, Wenwu Zhang","doi":"10.1155/2023/8880759","DOIUrl":"https://doi.org/10.1155/2023/8880759","url":null,"abstract":"This study introduces a novel phase compensation-based, asymmetric frequency selective surface (FSS). Aimed at enhancing angular stability, the phase compensation method utilizes the reflected phase gradient changes generated by two FSSs at large grazing angles. The ultimate improvement in angular stability comes from unit amalgamation to achieve phase complementarity, effectively dealing with the phase shift of incident waves caused by large grazing angles. Based on this principle, the asymmetric FSS structure is built with 3 components: a Minkowski fractal cell, a bent-line square-loop cell, and a thin square-loop parasitic cell. Simulation results show the structure demonstrates a 0 relative shift of resonant frequency within an incidence range of 0-80° under transverse electric (TE) polarization. However, it exhibits a maximum relative shift of 5.12% in resonant frequency at an 80° incidence under transverse magnetic (TM) polarization. Compared with E 1 and E 2 units, this structure significantly reduces frequency deviation—by 100% at 80° incidence under TE polarization and by 80.12% and 83.26% compared with E 1 and E 2 units under TM polarization. Finally, the proposed FSS model was fabricated and processed, with measured data basically aligning with the simulated results.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139273006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qingting He, Haiyan Chen, Qian Liu, Xin Yao, Fengxia Li, D. Liang, Jianliang Xie, Longjiang Deng
In this paper, it is proposed to employ phase cancellation metasurface (PCM) to substantially reduce the RCS of an electrically large open-ended cavity (EOC) by scattering the energy to the nonthreatening region, achieving broadband and ultra-wide-angle RCS reduction of the cavity. The PCM, constituted by the collection of polarizing reflectors, is loaded on the inner and outer walls of the composed cavity structure in accordance with the orthogonality principle to obtain a low-RCS cavity. The main benefits of using the polarizing reflector to build a PCM are as follows: On the one hand, it reduces the number of units that make up the PCM, which in principle only requires half of the quantity. On the other hand, it is possible to form a phase difference of 180 degrees that is completely stable. Both the simulation and measured results show that the RCS reduction of 10 dB for normal incidence relative to the original state of the cavity (that is, the metal cavity) over a frequency range of 6.3 GHz to 13.2 GHz under TE polarization and 7.8 GHz to 13.4 GHz under TM polarization has been obtained. Furthermore, the RCS reduction performances of the cavity loaded with the composed PCM under variable azimuth angles are also studied. Numerical and experimental results demonstrate that the ultra-wide-angle RCS reduction from -180° to 180° is acquired. To the best of our knowledge, this is the first time that the PCM, which is made up of a number of polarizing reflectors, has been used to get broadband and ultra-wide-angle RCS reduction for the EOC. This method, which is simple, effective, and low cost, has great application prospects in the RCS reduction design of the cavity.
{"title":"Design of Broadband and Ultra-Wide-Angle Low-RCS Open-Ended Cavity Based on Phase Cancellation","authors":"Qingting He, Haiyan Chen, Qian Liu, Xin Yao, Fengxia Li, D. Liang, Jianliang Xie, Longjiang Deng","doi":"10.1155/2023/9958074","DOIUrl":"https://doi.org/10.1155/2023/9958074","url":null,"abstract":"In this paper, it is proposed to employ phase cancellation metasurface (PCM) to substantially reduce the RCS of an electrically large open-ended cavity (EOC) by scattering the energy to the nonthreatening region, achieving broadband and ultra-wide-angle RCS reduction of the cavity. The PCM, constituted by the collection of polarizing reflectors, is loaded on the inner and outer walls of the composed cavity structure in accordance with the orthogonality principle to obtain a low-RCS cavity. The main benefits of using the polarizing reflector to build a PCM are as follows: On the one hand, it reduces the number of units that make up the PCM, which in principle only requires half of the quantity. On the other hand, it is possible to form a phase difference of 180 degrees that is completely stable. Both the simulation and measured results show that the RCS reduction of 10 dB for normal incidence relative to the original state of the cavity (that is, the metal cavity) over a frequency range of 6.3 GHz to 13.2 GHz under TE polarization and 7.8 GHz to 13.4 GHz under TM polarization has been obtained. Furthermore, the RCS reduction performances of the cavity loaded with the composed PCM under variable azimuth angles are also studied. Numerical and experimental results demonstrate that the ultra-wide-angle RCS reduction from -180° to 180° is acquired. To the best of our knowledge, this is the first time that the PCM, which is made up of a number of polarizing reflectors, has been used to get broadband and ultra-wide-angle RCS reduction for the EOC. This method, which is simple, effective, and low cost, has great application prospects in the RCS reduction design of the cavity.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139274138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuqing Yang, Weimin Wang, Yongle Wu, Bihua Tang, Yuanan Liu
In this paper, the impact of the intelligent reflecting surface (IRS) on the propagation characteristics is analyzed from the arguments of the physical and electromagnetic characteristics of the channel. Analytical expressions for free-space pathloss are derived based on the terahertz multiple-input multiple-output (MIMO) channel model in different communication scenarios. This calculation method is broadly applicable and is used to characterize pathloss as a function of the configuration of our system model. Numerical results show that setting the phase matrix of IRS based only on the angle of arrival (AoA) and angle of departure (AoD) can significantly reduce the pathloss when the far-field condition is met. However, when the distance between the transceiver and the IRS is the same order of magnitude or less than the side length of the IRS, both direction and distance information are required to configure the IRS. This model provides an insightful consideration in the design of IRS-assisted wireless system.
{"title":"Pathloss Modeling and Analysis for Intelligent Reflecting Surface-Assisted Terahertz MIMO Wireless Systems","authors":"Yuqing Yang, Weimin Wang, Yongle Wu, Bihua Tang, Yuanan Liu","doi":"10.1155/2023/6214342","DOIUrl":"https://doi.org/10.1155/2023/6214342","url":null,"abstract":"In this paper, the impact of the intelligent reflecting surface (IRS) on the propagation characteristics is analyzed from the arguments of the physical and electromagnetic characteristics of the channel. Analytical expressions for free-space pathloss are derived based on the terahertz multiple-input multiple-output (MIMO) channel model in different communication scenarios. This calculation method is broadly applicable and is used to characterize pathloss as a function of the configuration of our system model. Numerical results show that setting the phase matrix of IRS based only on the angle of arrival (AoA) and angle of departure (AoD) can significantly reduce the pathloss when the far-field condition is met. However, when the distance between the transceiver and the IRS is the same order of magnitude or less than the side length of the IRS, both direction and distance information are required to configure the IRS. This model provides an insightful consideration in the design of IRS-assisted wireless system.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fengming Yang, Xueting Yan, Huacheng Zhu, Yang Yang, Kama Huang
Cylindrical loads are commonly found in microwave heating. However, cylindrical loads tend to have a thermal focus, leading to uneven microwave heating. In this paper, a novel microwave heating method was proposed by employing resonant rings to mitigate the thermal focus of cylindrical loads. Firstly, a multiphysics simulation model for microwave heating of a cylindrical tube is established, and the influence of the resonant ring around the cylindrical tube on the temperature distribution of load was analyzed. Subsequently, microwave heating experiments of agar gels with and without resonant rings were carried out. In agreement with the simulation results, the use of resonant rings reduces the coefficient of temperature variation (COV) from 1.064 to 0.793. In addition, the parameters affecting the heating uniformity of the cylindrical tube were discussed through simulations.
{"title":"Mitigating Thermal Focusing in Microwave Heating of Cylindrical Loads by Resonant Rings","authors":"Fengming Yang, Xueting Yan, Huacheng Zhu, Yang Yang, Kama Huang","doi":"10.1155/2023/1668006","DOIUrl":"https://doi.org/10.1155/2023/1668006","url":null,"abstract":"Cylindrical loads are commonly found in microwave heating. However, cylindrical loads tend to have a thermal focus, leading to uneven microwave heating. In this paper, a novel microwave heating method was proposed by employing resonant rings to mitigate the thermal focus of cylindrical loads. Firstly, a multiphysics simulation model for microwave heating of a cylindrical tube is established, and the influence of the resonant ring around the cylindrical tube on the temperature distribution of load was analyzed. Subsequently, microwave heating experiments of agar gels with and without resonant rings were carried out. In agreement with the simulation results, the use of resonant rings reduces the coefficient of temperature variation (COV) from 1.064 to 0.793. In addition, the parameters affecting the heating uniformity of the cylindrical tube were discussed through simulations.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135216624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, a novel 1.8-5 GHz downconversion mixer is presented. The mixer is designed and simulated using SiGe 8HP 130 nm CMOS process technology. The proposed mixer is implemented by incorporating a double-balanced configuration, active inductor, and current mirror techniques. For performance optimization of the proposed mixer, different algorithms such as the genetic algorithm (GA), inclined plane system optimization (IPO) algorithm, and particle swarm optimization (PSO) algorithm have been used. Compared to existing works, this design shows an enhanced conversion gain (CG), a third-order input intercept point (IIP3), and return loss ( ) at the expense of the noise figure (NF). Additionally, the design consumes low power and covers a small chip area compared to other state-of-the-art devices. PSO shows the most promising results when compared to other optimization algorithms’ results. According to the measurement results after PSO optimization, the mixer attains a maximum CG of 25 dB, an IIP3 of 4 dBm, and a NF of 5.2 dB at 5 GHz, while consuming only 15 mW of DC power. The mixer operates at 1.2 V and covers 0.8 mm2 die area.
{"title":"Performance Analysis of a Reconfigurable Mixer Using Particle Swarm Optimization","authors":"Shilpa Mehta, Xue Jun Li, Massimo Donelli","doi":"10.1155/2023/3786691","DOIUrl":"https://doi.org/10.1155/2023/3786691","url":null,"abstract":"In this article, a novel 1.8-5 GHz downconversion mixer is presented. The mixer is designed and simulated using SiGe 8HP 130 nm CMOS process technology. The proposed mixer is implemented by incorporating a double-balanced configuration, active inductor, and current mirror techniques. For performance optimization of the proposed mixer, different algorithms such as the genetic algorithm (GA), inclined plane system optimization (IPO) algorithm, and particle swarm optimization (PSO) algorithm have been used. Compared to existing works, this design shows an enhanced conversion gain (CG), a third-order input intercept point (IIP3), and return loss ( <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>11</mn> </mrow> </msub> </math> ) at the expense of the noise figure (NF). Additionally, the design consumes low power and covers a small chip area compared to other state-of-the-art devices. PSO shows the most promising results when compared to other optimization algorithms’ results. According to the measurement results after PSO optimization, the mixer attains a maximum CG of 25 dB, an IIP3 of 4 dBm, and a NF of 5.2 dB at 5 GHz, while consuming only 15 mW of DC power. The mixer operates at 1.2 V and covers 0.8 mm2 die area.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135567335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conical beam antenna plays a significant role in providing stable access to satellite signals for moving communication terminals. Although metasurfaces have been used to generate conical beams, most of them can only reflect conical beams with identically distributed and mirror-symmetric phase responses for left-hand circular polarization and right-hand circular polarization, which can hinder the dual-polarization applications of metasurfaces. In this study, a metasurface is designed to independently manipulate dual-polarized excitations in broadband. To achieve the broadband control of conical beams, broadband conditions for both geometric and propagation phases are developed. Differently, metasurface designed in this study consists of three types of distinguishingly shaped elements, which can provide more degree of freedom in dual-polarization broadband design. In addition, a design method is developed for metasurface to generate the cone angle tailorable conical beams. Via fabricating a metasurface following the proposed method, the designed metasurface is verified in theorem, simulation, and experiment that it can generate desired conical beams with tailored divergent angles and phase responses covering a bandwidth from 12.5 GHz to 17 GHz.
{"title":"Broadband Polarization-Decoupled Metasurface for Generating Tailored Dual-Polarization Conical Beams","authors":"Lingjun Yang, Beier Ying, Sheng Sun","doi":"10.1155/2023/3599970","DOIUrl":"https://doi.org/10.1155/2023/3599970","url":null,"abstract":"Conical beam antenna plays a significant role in providing stable access to satellite signals for moving communication terminals. Although metasurfaces have been used to generate conical beams, most of them can only reflect conical beams with identically distributed and mirror-symmetric phase responses for left-hand circular polarization and right-hand circular polarization, which can hinder the dual-polarization applications of metasurfaces. In this study, a metasurface is designed to independently manipulate dual-polarized excitations in broadband. To achieve the broadband control of conical beams, broadband conditions for both geometric and propagation phases are developed. Differently, metasurface designed in this study consists of three types of distinguishingly shaped elements, which can provide more degree of freedom in dual-polarization broadband design. In addition, a design method is developed for metasurface to generate the cone angle tailorable conical beams. Via fabricating a metasurface following the proposed method, the designed metasurface is verified in theorem, simulation, and experiment that it can generate desired conical beams with tailored divergent angles and phase responses covering a bandwidth from 12.5 GHz to 17 GHz.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135767017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a wideband cavity-backed slot antenna array designed for X-band wireless communication systems. The antenna element consists of a circular slot combined with a cross-slotted patch; both are fed by an L-shaped microstrip line through proximity coupling to extend the impedance bandwidth and gain. The reduction of beam squint in the radiation patterns, caused by the asymmetric feed line, is achieved through intelligent optimization of the dimensions and position of the cross slot on the patch. Additionally, a back cavity is included to provide unidirectional radiation and enhance gain. The antenna exhibits right-hand circularly polarized (RHCP) radiation patterns with high gain over a wideband frequency range. To further improve the axial ratio (AR) bandwidth and gain, the antenna is utilized in a array configuration with a sequential rotation feed network. The overall dimensions of the proposed array are , where represents the wavelength at the center frequency of 10 GHz. The fabricated array is then tested, and the measurements show an impedance bandwidth of 60% (7 GHz-13 GHz) with dB, a 3 dB AR bandwidth of 42% (7.45-11.65 GHz), and a peak gain of 11.14 dB. The simulated and measured results exhibit good agreement, validating the effectiveness of the design.
{"title":"Development of a Broadband and High-Gain Circularly Polarized Array of Multilayer Slot Antennas for X-Band Wireless Communication Networks","authors":"Hosein Saghafi, Robab Kazemi, Hamed Hamlbar Gerami","doi":"10.1155/2023/8701539","DOIUrl":"https://doi.org/10.1155/2023/8701539","url":null,"abstract":"This paper presents a wideband cavity-backed slot antenna array designed for X-band wireless communication systems. The antenna element consists of a circular slot combined with a cross-slotted patch; both are fed by an L-shaped microstrip line through proximity coupling to extend the impedance bandwidth and gain. The reduction of beam squint in the radiation patterns, caused by the asymmetric feed line, is achieved through intelligent optimization of the dimensions and position of the cross slot on the patch. Additionally, a back cavity is included to provide unidirectional radiation and enhance gain. The antenna exhibits right-hand circularly polarized (RHCP) radiation patterns with high gain over a wideband frequency range. To further improve the axial ratio (AR) bandwidth and gain, the antenna is utilized in a <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <mn>2</mn> <mo>×</mo> <mn>2</mn> </math> array configuration with a sequential rotation feed network. The overall dimensions of the proposed array are <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"> <mn>1.42</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> <mo>×</mo> <mn>1.42</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> <mo>×</mo> <mn>0.45</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> </math> , where <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\"> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> </math> represents the wavelength at the center frequency of 10 GHz. The fabricated array is then tested, and the measurements show an impedance bandwidth of 60% (7 GHz-13 GHz) with <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\"> <mfenced open=\"|\" close=\"|\"> <mrow> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>11</mn> </mrow> </msub> </mrow> </mfenced> <mo><</mo> <mo>−</mo> <mn>10</mn> </math> dB, a 3 dB AR bandwidth of 42% (7.45-11.65 GHz), and a peak gain of 11.14 dB. The simulated and measured results exhibit good agreement, validating the effectiveness of the design.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136013200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kingsford Sarkodie Obeng Kwakye, Nouman Rasool, Kwame Oteng Gyasi, Joseph Abroquah, Mubarak Sani Ellis, Ohemeng Lord Owusu, Abdul-Rahman Ahmed, Jerry John Kponyo
This paper presents the design of a simple dual-band circularly polarized monopole antenna using characteristic mode analysis. First, a dual-band elliptically polarized “L”-shaped monopole antenna with a partial ground is designed; then, a rectangular stub and a parasitic structure on the ground plane are implemented to achieve dual-band CP operation. To enhance impedance bandwidth and generate circular polarization in the upper band, the rectangular stub is attached to the “L”-shaped strip. The parasitic structure is employed for simultaneous dual-band CP radiation. Characteristic mode analysis is undertaken to predict the performance of the antenna before excitation. The modal analysis which is undertaken before excitation shows the natural modes that can be excited by the antenna structure to generate a dual-band CP response. The analysis gives approximate bandwidths that can be achieved by the antenna even before excitation. The overall dimension of the antenna , where is the corresponding free-space wavelength at 5.7 GHz. The measured -10 dB impedance bandwidth (ZBW) is realized to be 75.9% (4.5 GHz–10 GHz). The measured 3 dB axial ratio bandwidths (ARBW) at the lower and upper bands are 6% (5.6 GHz–5.95 GHz) and 28% (6.65 GHz–8.82 GHz), respectively. The proposed antenna features a simple and compact structure for Wi-Fi, WLAN, WiMAX, and C band applications.
{"title":"Design and Analysis of a Low-Profile Dual-Band Circularly Polarized Monopole Antenna Based on Characteristic Mode Analysis","authors":"Kingsford Sarkodie Obeng Kwakye, Nouman Rasool, Kwame Oteng Gyasi, Joseph Abroquah, Mubarak Sani Ellis, Ohemeng Lord Owusu, Abdul-Rahman Ahmed, Jerry John Kponyo","doi":"10.1155/2023/7855907","DOIUrl":"https://doi.org/10.1155/2023/7855907","url":null,"abstract":"This paper presents the design of a simple dual-band circularly polarized monopole antenna using characteristic mode analysis. First, a dual-band elliptically polarized “L”-shaped monopole antenna with a partial ground is designed; then, a rectangular stub and a parasitic structure on the ground plane are implemented to achieve dual-band CP operation. To enhance impedance bandwidth and generate circular polarization in the upper band, the rectangular stub is attached to the “L”-shaped strip. The parasitic structure is employed for simultaneous dual-band CP radiation. Characteristic mode analysis is undertaken to predict the performance of the antenna before excitation. The modal analysis which is undertaken before excitation shows the natural modes that can be excited by the antenna structure to generate a dual-band CP response. The analysis gives approximate bandwidths that can be achieved by the antenna even before excitation. The overall dimension of the antenna <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <mtext mathvariant=\"italic\">is</mtext> <mtext> </mtext> <mn>0.379</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> <mo>×</mo> <mn>0.379</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> <mo>×</mo> <mn>0.015</mn> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> </math> , where <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"> <msub> <mrow> <mi>λ</mi> </mrow> <mrow> <mn>0</mn> </mrow> </msub> </math> is the corresponding free-space wavelength at 5.7 GHz. The measured -10 dB impedance bandwidth (ZBW) is realized to be 75.9% (4.5 GHz–10 GHz). The measured 3 dB axial ratio bandwidths (ARBW) at the lower and upper bands are 6% (5.6 GHz–5.95 GHz) and 28% (6.65 GHz–8.82 GHz), respectively. The proposed antenna features a simple and compact structure for Wi-Fi, WLAN, WiMAX, and C band applications.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135251958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A circular polarization (CP) antenna that can switch between right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) modes has been designed and introduced for 5G applications in the 3.5 GHz frequency band in this work. The proposed antenna comprises a crossed dipole fed by a 90° hybrid coupler. The axial ratio (AR) enhancement of 190 MHz is achieved by vertically stacking a substrate with a distance of from the ground plane, including an annular ring-shaped parasitic element above a circular-shaped disc. Consequently, by creating surface current rotation on the parasitic elements, the CP performance of the antenna is improved. According to the experiments, a wide impedance bandwidth of 930 MHz (3.19-4.12 GHz) and an overlapped AR bandwidth of 23.5% for both modes are achieved. The overall size of the antenna is , and the gain is stable across the operating frequency band with a peak value of 6.78 dBic.
{"title":"Axial Ratio Improvement of Circularly Polarized Antenna Using Parasitic Elements for 5G Applications","authors":"Samira Mohammadkhani, Alireza Mallahzadeh","doi":"10.1155/2023/6619073","DOIUrl":"https://doi.org/10.1155/2023/6619073","url":null,"abstract":"A circular polarization (CP) antenna that can switch between right-handed circular polarization (RHCP) and left-handed circular polarization (LHCP) modes has been designed and introduced for 5G applications in the 3.5 GHz frequency band in this work. The proposed antenna comprises a crossed dipole fed by a 90° hybrid coupler. The axial ratio (AR) enhancement of 190 MHz is achieved by vertically stacking a substrate with a distance of <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <mi>λ</mi> <mo>/</mo> <mn>4</mn> </math> from the ground plane, including an annular ring-shaped parasitic element above a circular-shaped disc. Consequently, by creating surface current rotation on the parasitic elements, the CP performance of the antenna is improved. According to the experiments, a wide impedance bandwidth of 930 MHz (3.19-4.12 GHz) and an overlapped AR bandwidth of 23.5% for both modes are achieved. The overall size of the antenna is <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"> <mn>100</mn> <mo>×</mo> <mn>92.5</mn> <mo>×</mo> <mn>24</mn> <mtext> </mtext> <mtext>m</mtext> <msup> <mrow> <mtext>m</mtext> </mrow> <mrow> <mn>3</mn> </mrow> </msup> </math> , and the gain is stable across the operating frequency band with a peak value of 6.78 dBic.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135689806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents a simple planar millimeter-wave (mm-wave) multiple input multiple output (MIMO) antenna with four closely spaced radiating elements. The antenna is intended to enhance the bandwidth for 5G new radio (NR) applications and also cover the industrial Ka-band (26.5-40 GHz), Q-band (30-50 GHz), and U-band (40-60 GHz) frequency ranges. The antenna is designed using Rogers RT/duroid 5880 substrate with a size of mm3. The proposed antenna consists of four identical radiating elements with two of them positioned in a linear configuration facing each other, while the other two elements are placed opposite to the first two, which improves isolation between the elements. Across the entire operating frequency range (26-60 GHz), the antenna demonstrated excellent performance, including 34 GHz wide bandwidth, high isolation of >25 dB, nearly omnidirectional radiation patterns, high gain of 11.1 dB with a high radiation efficiency of 94%, low envelope correlation coefficient (ECC) of 0.0068, and high diversity gain (DG) of 9.967 dB. The simulated findings exhibit a strong positive correlation with the experimental results. The proposed MIMO antenna design is a promising solution for 5G NR applications.
{"title":"A High-Frequency Planar-Configured Millimeter-Wave MIMO Antenna for Fifth-Generation NR Operations","authors":"Poonam Tiwari, Vishant Gahlaut, Meenu Kaushik, Anshuman Shastri, Gulman Siddiqui, Bhupender Singh","doi":"10.1155/2023/9533725","DOIUrl":"https://doi.org/10.1155/2023/9533725","url":null,"abstract":"This article presents a simple planar millimeter-wave (mm-wave) multiple input multiple output (MIMO) antenna with four closely spaced radiating elements. The antenna is intended to enhance the bandwidth for 5G new radio (NR) applications and also cover the industrial Ka-band (26.5-40 GHz), Q-band (30-50 GHz), and U-band (40-60 GHz) frequency ranges. The antenna is designed using Rogers RT/duroid 5880 substrate with a size of <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"> <mn>25</mn> <mo>×</mo> <mn>26</mn> <mo>×</mo> <mn>1.6</mn> </math> mm3. The proposed antenna consists of four identical radiating elements with two of them positioned in a linear configuration facing each other, while the other two elements are placed opposite to the first two, which improves isolation between the elements. Across the entire operating frequency range (26-60 GHz), the antenna demonstrated excellent performance, including 34 GHz wide bandwidth, high isolation of >25 dB, nearly omnidirectional radiation patterns, high gain of 11.1 dB with a high radiation efficiency of 94%, low envelope correlation coefficient (ECC) of 0.0068, and high diversity gain (DG) of 9.967 dB. The simulated findings exhibit a strong positive correlation with the experimental results. The proposed MIMO antenna design is a promising solution for 5G NR applications.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136248786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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