Pub Date : 2024-09-04DOI: 10.1109/OJAP.2024.3454330
Jia-Xiang Hao;Hui-Dong Li;Lei Zhu
This article proposes a design method for a circularly-polarized (CP) antenna, which is realized by using coupling effects. Initially, the desired electric(magnetic) coupling between two identical $lambda$ /4 short-circuited microstrip line (MS-L) resonators can be generated when the short-circuited (opencircuited) ends of the resonators are in close proximity to each other. Besides, an orthogonal arrangement in space for these two resonators has been adopted to yield two orthogonal linearly-polarized (LP) waves. Therefore, a desired CP rotation can be achieved by choosing corresponding coupling types. Meanwhile, two equivalent circuit models are established and analyzed to deduce the formulas of the mutual inductance and mutual capacitance for the desired CP radiation. Afterwards, a binary array consisting of a magnetically coupled (MC) pair of resonators and an electrically coupled (EC) pair of resonators is proposed for expanding the axial ratio bandwidth (ARBW) and enhancing peak gain. Finally, a right-handed circularlypolarized (RHCP) antenna with magnetic coupling, a left-handed circularly-polarized (LHCP) antenna with electric coupling and a binary array are fabricated and tested. And an excellent agreement is validated between the experiment and simulation results. The measured results show that the binary array achieves a maximum gain of 5 dBic within its measured ARBW range of 3.535 – 3.615 GHz. In contrast, the single pairs (EC or MC pair) exhibit a gain of 3 dBic. Additionally, the array demonstrates a fivefold expansion in ARBW compared to the single pair.
{"title":"Design of a Circularly-Polarized Microstrip Antenna by Utilizing Mutually-Coupled Resonators","authors":"Jia-Xiang Hao;Hui-Dong Li;Lei Zhu","doi":"10.1109/OJAP.2024.3454330","DOIUrl":"10.1109/OJAP.2024.3454330","url":null,"abstract":"This article proposes a design method for a circularly-polarized (CP) antenna, which is realized by using coupling effects. Initially, the desired electric(magnetic) coupling between two identical \u0000<inline-formula> <tex-math>$lambda$ </tex-math></inline-formula>\u0000/4 short-circuited microstrip line (MS-L) resonators can be generated when the short-circuited (opencircuited) ends of the resonators are in close proximity to each other. Besides, an orthogonal arrangement in space for these two resonators has been adopted to yield two orthogonal linearly-polarized (LP) waves. Therefore, a desired CP rotation can be achieved by choosing corresponding coupling types. Meanwhile, two equivalent circuit models are established and analyzed to deduce the formulas of the mutual inductance and mutual capacitance for the desired CP radiation. Afterwards, a binary array consisting of a magnetically coupled (MC) pair of resonators and an electrically coupled (EC) pair of resonators is proposed for expanding the axial ratio bandwidth (ARBW) and enhancing peak gain. Finally, a right-handed circularlypolarized (RHCP) antenna with magnetic coupling, a left-handed circularly-polarized (LHCP) antenna with electric coupling and a binary array are fabricated and tested. And an excellent agreement is validated between the experiment and simulation results. The measured results show that the binary array achieves a maximum gain of 5 dBic within its measured ARBW range of 3.535 – 3.615 GHz. In contrast, the single pairs (EC or MC pair) exhibit a gain of 3 dBic. Additionally, the array demonstrates a fivefold expansion in ARBW compared to the single pair.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1747-1757"},"PeriodicalIF":3.5,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10664594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1109/OJAP.2024.3454120
Xi Liao;Ping Zhou;Yang Wang;Jie Zhang
Sub-Terahertz communication has broad application prospects for realizing ultra-broadband sixth generation (6G) system. One fundamental challenge when moving to new spectrum is to understand the science of radio propagation and propose an accurate and effective channel prediction method. In this paper, we first conduct extensive vector network analyzer-based radio propagation measurements at 140 GHz and 220 GHz in indoor hallway and lobby environments and at 280 GHz in an indoor laboratory environment. Omnidirectional and best directional path loss are modeled by empirical single-band and multi-band path loss models. Numerical results demonstrate that large-scale close-in model in this paper is simpler and more physically-based compared to floating-intercept model. In particular, a path loss prediction method based on environment features is proposed, which can predict path loss directly by utilizing random forest method, and the propagation environment are defined and extracted by scatterer features and related features of the transmitter and receiver. The performance of the proposed method is better than that of empirical path loss models. The measured results not only enrich the datasets of indoor sub-THz channel propagation, also can guide communication systems, network planning and deployment for 6G and beyond.
{"title":"Path Loss Modeling and Environment Features Powered Prediction for Sub-THz Communication","authors":"Xi Liao;Ping Zhou;Yang Wang;Jie Zhang","doi":"10.1109/OJAP.2024.3454120","DOIUrl":"10.1109/OJAP.2024.3454120","url":null,"abstract":"Sub-Terahertz communication has broad application prospects for realizing ultra-broadband sixth generation (6G) system. One fundamental challenge when moving to new spectrum is to understand the science of radio propagation and propose an accurate and effective channel prediction method. In this paper, we first conduct extensive vector network analyzer-based radio propagation measurements at 140 GHz and 220 GHz in indoor hallway and lobby environments and at 280 GHz in an indoor laboratory environment. Omnidirectional and best directional path loss are modeled by empirical single-band and multi-band path loss models. Numerical results demonstrate that large-scale close-in model in this paper is simpler and more physically-based compared to floating-intercept model. In particular, a path loss prediction method based on environment features is proposed, which can predict path loss directly by utilizing random forest method, and the propagation environment are defined and extracted by scatterer features and related features of the transmitter and receiver. The performance of the proposed method is better than that of empirical path loss models. The measured results not only enrich the datasets of indoor sub-THz channel propagation, also can guide communication systems, network planning and deployment for 6G and beyond.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1734-1746"},"PeriodicalIF":3.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1109/OJAP.2024.3449752
Mahrukh Khan;Talha Murad;Nicholas Lusdyk
This paper presents a novel and insightful approach to beamforming a $2times 2$ antenna array using the theory of characteristic modes. The array comprises four rectangular patch antenna elements designed on an FR-4 substrate resonating at 2.4 GHz. The characteristic mode analysis (CMA) presented a fascinating physical insight into the surface current directions and the radiation characteristics of the array structure. The excitation of a specific characteristic mode led to the design of a dual-beam antenna array. After feed excitation, characteristic mode analysis (CMA) was employed to understand multi-beam pattern reconfigurability in the multi-port structure. The information of distinct and orthogonal modal characteristic fields guides the beamforming of multibeam arrays. Modal characteristic fields of specific modes were identified using a modal weighting coefficient that may combine upon port phase change for beamforming at a certain scan angle. The potential of multi-dimensional coverage of a multibeam array is presented by selecting the different phase combinations of feeding ports. The paper discusses the strengths and limitations of beam scanning due to the combination of modes. This physical insight is beneficial for future pattern reconfigurable antenna array design procedures. Measurements on a realized prototype are in a good agreement with simulations, proving the proposed concept.
{"title":"Beamforming Analysis of Dual Beam Antenna Array Using Theory of Characteristic Modes","authors":"Mahrukh Khan;Talha Murad;Nicholas Lusdyk","doi":"10.1109/OJAP.2024.3449752","DOIUrl":"10.1109/OJAP.2024.3449752","url":null,"abstract":"This paper presents a novel and insightful approach to beamforming a \u0000<inline-formula> <tex-math>$2times 2$ </tex-math></inline-formula>\u0000 antenna array using the theory of characteristic modes. The array comprises four rectangular patch antenna elements designed on an FR-4 substrate resonating at 2.4 GHz. The characteristic mode analysis (CMA) presented a fascinating physical insight into the surface current directions and the radiation characteristics of the array structure. The excitation of a specific characteristic mode led to the design of a dual-beam antenna array. After feed excitation, characteristic mode analysis (CMA) was employed to understand multi-beam pattern reconfigurability in the multi-port structure. The information of distinct and orthogonal modal characteristic fields guides the beamforming of multibeam arrays. Modal characteristic fields of specific modes were identified using a modal weighting coefficient that may combine upon port phase change for beamforming at a certain scan angle. The potential of multi-dimensional coverage of a multibeam array is presented by selecting the different phase combinations of feeding ports. The paper discusses the strengths and limitations of beam scanning due to the combination of modes. This physical insight is beneficial for future pattern reconfigurable antenna array design procedures. Measurements on a realized prototype are in a good agreement with simulations, proving the proposed concept.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1465-1475"},"PeriodicalIF":3.5,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10646390","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1109/OJAP.2024.3448245
Elizvan Juarez;Marco A. Panduro;David H. Covarrubias;Alberto Reyna
This paper presents a new design proposal for the simplification of linear beam-forming networks by applying a novel phase interpolation technique. This paper proposes the strategic utilization of 1-to-3 division nodes and 2-to-1 recombination nodes to reconstructing the cophasal values necessary for radiation beam scanning in linear phased array systems. This novel technique simplifies the beam-forming network, achieving a reduction of phase shifters by up to 60% and ±18° of scan angle. These benefits are obtained using uniform amplitude excitation and without additional amplitude controls. The complete antenna system considers a broadband V-slot as antenna element for obtaining a bandwidth performance of approximately 1.2 GHz. This results in a 22% of bandwidth. This is illustrated by using a prototype with experimental measurement results and simulations based on electromagnetic solver (CST Microwave Studio). These results reveal an interesting reduction of phase shifters for a good trade-off of beam-steering range and bandwidth behavior. The experimental results are analyzed and compared with other techniques and previous works cited in the literature. This novel methodology provides interesting results of a high benefit for wireless applications of phased antenna systems.
{"title":"Simplification of Linear Beam-Forming Networks by Applying a Novel Phase Interpolation Technique","authors":"Elizvan Juarez;Marco A. Panduro;David H. Covarrubias;Alberto Reyna","doi":"10.1109/OJAP.2024.3448245","DOIUrl":"10.1109/OJAP.2024.3448245","url":null,"abstract":"This paper presents a new design proposal for the simplification of linear beam-forming networks by applying a novel phase interpolation technique. This paper proposes the strategic utilization of 1-to-3 division nodes and 2-to-1 recombination nodes to reconstructing the cophasal values necessary for radiation beam scanning in linear phased array systems. This novel technique simplifies the beam-forming network, achieving a reduction of phase shifters by up to 60% and ±18° of scan angle. These benefits are obtained using uniform amplitude excitation and without additional amplitude controls. The complete antenna system considers a broadband V-slot as antenna element for obtaining a bandwidth performance of approximately 1.2 GHz. This results in a 22% of bandwidth. This is illustrated by using a prototype with experimental measurement results and simulations based on electromagnetic solver (CST Microwave Studio). These results reveal an interesting reduction of phase shifters for a good trade-off of beam-steering range and bandwidth behavior. The experimental results are analyzed and compared with other techniques and previous works cited in the literature. This novel methodology provides interesting results of a high benefit for wireless applications of phased antenna systems.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1714-1723"},"PeriodicalIF":3.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10643585","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1109/OJAP.2024.3448253
Demos Serghiou;Mohsen Khalily;Tim W. C. Brown;Rahim Tafazolli
This paper presents wideband channel measurements for indoor Non-Line-of-Sight (NLoS) fixed links operating at sub-Terahertz (sub-THz) frequencies (92.110 GHz) with single scattered reflections. Seemingly “smooth” surfaces generate substantial internal multipath causing frequency selective scattered reflections owing to the short wavelength. Unlike specular reflections, no single well-defined reflection point aligns the incidence angle ( $theta_{{mathrm {i}}}$ ) and reflection angle ( $theta_{{mathrm {r}}}$ ) to form the lowest path loss. This means that the scattering effect of the reflective surface gives reason to search for the best angular alignment of the Receiver (Rx) antenna given a specific angle from the Transmitter (Tx) antenna. The wideband effective Radar Cross Section (RCS) is derived and computed based on the bi-static radar equation, which specifically accounts for the effect of alignment angle on the defined frequency selective RCS. The measurements reveal alignment-variant angular scattering from large-scale discontinuities such as wall partitions, television screens and metallic reinforcement studs, offering valuable insights for the design and deployment of future wireless communications systems operating in the sub-THz band.
{"title":"Characterization of Effective RCS for Fixed NLoS Sub-THz Links With Single Scattered Reflections","authors":"Demos Serghiou;Mohsen Khalily;Tim W. C. Brown;Rahim Tafazolli","doi":"10.1109/OJAP.2024.3448253","DOIUrl":"10.1109/OJAP.2024.3448253","url":null,"abstract":"This paper presents wideband channel measurements for indoor Non-Line-of-Sight (NLoS) fixed links operating at sub-Terahertz (sub-THz) frequencies (92.110 GHz) with single scattered reflections. Seemingly “smooth” surfaces generate substantial internal multipath causing frequency selective scattered reflections owing to the short wavelength. Unlike specular reflections, no single well-defined reflection point aligns the incidence angle (\u0000<inline-formula> <tex-math>$theta_{{mathrm {i}}}$ </tex-math></inline-formula>\u0000) and reflection angle (\u0000<inline-formula> <tex-math>$theta_{{mathrm {r}}}$ </tex-math></inline-formula>\u0000) to form the lowest path loss. This means that the scattering effect of the reflective surface gives reason to search for the best angular alignment of the Receiver (Rx) antenna given a specific angle from the Transmitter (Tx) antenna. The wideband effective Radar Cross Section (RCS) is derived and computed based on the bi-static radar equation, which specifically accounts for the effect of alignment angle on the defined frequency selective RCS. The measurements reveal alignment-variant angular scattering from large-scale discontinuities such as wall partitions, television screens and metallic reinforcement studs, offering valuable insights for the design and deployment of future wireless communications systems operating in the sub-THz band.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1724-1733"},"PeriodicalIF":3.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10643561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1109/OJAP.2024.3446914
Hamad M. Alkhoori;Mousa Hussein
The radiation of a structure comprising a spherical radome enclosing an antenna and made of an orthorhombic dielectric-magnetic medium is treated semi analytically in this paper. Inside the radome, the radiation field phasors due to the antenna and reflected field phasors due to the radome are expanded into vector spherical wave functions of the radome’s medium. This yields two sets of unknown expansion coefficients: the radiation-field expansion coefficients, and the reflected-field expansion coefficients. The radiation-field expansion coefficients are obtained in terms of the current distribution in the antenna upon using the bilinear-form dyadic Green functions of the radome’s medium. Outside the radome, the exterior field phasors due to the radome and the antenna are expanded into the conventional vector spherical wave functions of free space, yielding unknown exterior-field coefficients. Application of standard boundary conditions across the radome’s surface yields the reflected and exterior-field coefficients in terms of the radiation-field coefficients, from which the radiation-field resistance and gain of the radome-antenna structure are calculated. For numerical illustration, as a nontrivial example, we considered a toroidal antenna carrying a uniform current distribution. The role of the anisotropy of the radome on the radiation resistance of the toroidal antenna is dictated by (i) the electrical size of the radome, (ii) the radome’s relative impedance, and (iii) the distinguished axis of the radome’s medium. Moreover, those factors can be used in shaping the gain pattern, as well as in raising or lowering the maximum gain.
{"title":"Radiation of an Antenna Enclosed by a Spherical Radome Made of an Orthorhombic Dielectric-Magnetic Medium","authors":"Hamad M. Alkhoori;Mousa Hussein","doi":"10.1109/OJAP.2024.3446914","DOIUrl":"10.1109/OJAP.2024.3446914","url":null,"abstract":"The radiation of a structure comprising a spherical radome enclosing an antenna and made of an orthorhombic dielectric-magnetic medium is treated semi analytically in this paper. Inside the radome, the radiation field phasors due to the antenna and reflected field phasors due to the radome are expanded into vector spherical wave functions of the radome’s medium. This yields two sets of unknown expansion coefficients: the radiation-field expansion coefficients, and the reflected-field expansion coefficients. The radiation-field expansion coefficients are obtained in terms of the current distribution in the antenna upon using the bilinear-form dyadic Green functions of the radome’s medium. Outside the radome, the exterior field phasors due to the radome and the antenna are expanded into the conventional vector spherical wave functions of free space, yielding unknown exterior-field coefficients. Application of standard boundary conditions across the radome’s surface yields the reflected and exterior-field coefficients in terms of the radiation-field coefficients, from which the radiation-field resistance and gain of the radome-antenna structure are calculated. For numerical illustration, as a nontrivial example, we considered a toroidal antenna carrying a uniform current distribution. The role of the anisotropy of the radome on the radiation resistance of the toroidal antenna is dictated by (i) the electrical size of the radome, (ii) the radome’s relative impedance, and (iii) the distinguished axis of the radome’s medium. Moreover, those factors can be used in shaping the gain pattern, as well as in raising or lowering the maximum gain.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1704-1713"},"PeriodicalIF":3.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10643140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20DOI: 10.1109/ojap.2024.3446595
Zixiang Han, Yujie Zhang, Jing Jin, Qixing Wang, Guangyi Liu
{"title":"A Novel Energy Efficient Single-RF MIMO Antenna Combining Load Modulated Array and ESPAR","authors":"Zixiang Han, Yujie Zhang, Jing Jin, Qixing Wang, Guangyi Liu","doi":"10.1109/ojap.2024.3446595","DOIUrl":"https://doi.org/10.1109/ojap.2024.3446595","url":null,"abstract":"","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1109/OJAP.2024.3445270
Reza Masoumi;Robab Kazemi;Aly E. Fathy
Employing two closely spaced arrays operating at the same frequency with orthogonal polarizations and independent operations present significant potential for miniaturizing telecommunication systems. This paper presents two interleaved, tightly spaced circular patch array antennas that operate at the same frequency but with orthogonal polarizations. The arrays are arranged in the E-plane, with one array rotated 90 degrees to achieve orthogonal polarization—Array-I is x-polarized, while Array-II is y-polarized. This configuration provides both spatial and polarization diversity, which helps reduce signal degradation caused by multipath fading and enhances overall channel capacity. However, the inherent symmetry of the circular patches typically results in significant coupling between adjacent arrays when they are closely spaced, which can severely degrade antenna performance. In this study, we investigate the effectiveness of conformal mantle cloaks and decoupling patches in isolating two interleaved co-frequency circular patch array antennas. Our designed mantle cloak, composed of a conformal substrate with parallel metallic strips, successfully eliminates cross-coupling between adjacent elements in the interleaved arrays, although it does not fully mitigate inter-element coupling within each array. To further address this issue, we employ small patches with shorting pins to minimize mutual coupling among the elements of each array. These isolating techniques enable minimal proximity between the arrays, achieving a center-to-center spacing of 28.88 mm ( $0.54lambda _{0}$ ) and an edge-to-edge gap of less than 1 mm ( $lambda _{0}$ /50), theoretically approaching zero at the resonant frequency of 5.6 GHz. The conformal substrate of the cloak, produced using 3D printing technology, simplifies the fabrication process by covering only the top surface of the patches. The proposed design has been successfully fabricated and evaluated using detailed comparison metrics, including return loss, mutual coupling, radiation patterns, gain, and efficiency across cloaked and uncloaked configurations. The simulation and experimental results closely match, confirming that the cloaked antennas exhibit similar radiation performance to isolated elements.
采用两个紧密间隔的阵列在同一频率下工作，具有正交的极化和独立的操作，为电信系统的小型化带来了巨大的潜力。本文介绍了两个交错、紧密间隔的圆形贴片阵列天线，它们工作在同一频率，但具有正交的极化。阵列排列在 E 平面上，其中一个阵列旋转 90 度以实现正交极化--阵列-I 为 x 极化，而阵列-II 为 y 极化。这种配置提供了空间和极化分集，有助于减少多径衰落造成的信号劣化，并提高整体信道容量。然而，圆形贴片固有的对称性通常会导致相邻阵列间距过近时产生明显的耦合，从而严重降低天线性能。在本研究中，我们研究了保形地幔斗篷和去耦贴片在隔离两个交错共频圆形贴片阵列天线方面的有效性。我们设计的地幔斗篷由带平行金属条的共形基板组成，它成功地消除了交错阵列中相邻元件之间的交叉耦合，但并不能完全缓解每个阵列内的元件间耦合。为了进一步解决这个问题，我们采用了带有短路引脚的小补丁，以最大限度地减少每个阵列中元件之间的相互耦合。这些隔离技术使阵列之间的距离达到最小，中心到中心的间距为 28.88 毫米（$0.54lambda _{0}$），边缘到边缘的间隙小于 1 毫米（$lambda _{0}$ /50），理论上在共振频率为 5.6 GHz 时接近零。斗篷的保形基底采用三维打印技术制作，只覆盖贴片的顶面，简化了制作过程。该设计方案已成功制作完成，并使用详细的比较指标进行了评估，包括隐身和非隐身配置的回波损耗、相互耦合、辐射模式、增益和效率。仿真和实验结果非常吻合，证实了隐形天线的辐射性能与孤立元件相似。
{"title":"Optimizing Isolation in Interleaved Co-Frequency Orthogonally Polarized Circular Patch Array Antennas Using Conformal Mantle Cloaks and Integrated Decoupling Patches","authors":"Reza Masoumi;Robab Kazemi;Aly E. Fathy","doi":"10.1109/OJAP.2024.3445270","DOIUrl":"10.1109/OJAP.2024.3445270","url":null,"abstract":"Employing two closely spaced arrays operating at the same frequency with orthogonal polarizations and independent operations present significant potential for miniaturizing telecommunication systems. This paper presents two interleaved, tightly spaced circular patch array antennas that operate at the same frequency but with orthogonal polarizations. The arrays are arranged in the E-plane, with one array rotated 90 degrees to achieve orthogonal polarization—Array-I is x-polarized, while Array-II is y-polarized. This configuration provides both spatial and polarization diversity, which helps reduce signal degradation caused by multipath fading and enhances overall channel capacity. However, the inherent symmetry of the circular patches typically results in significant coupling between adjacent arrays when they are closely spaced, which can severely degrade antenna performance. In this study, we investigate the effectiveness of conformal mantle cloaks and decoupling patches in isolating two interleaved co-frequency circular patch array antennas. Our designed mantle cloak, composed of a conformal substrate with parallel metallic strips, successfully eliminates cross-coupling between adjacent elements in the interleaved arrays, although it does not fully mitigate inter-element coupling within each array. To further address this issue, we employ small patches with shorting pins to minimize mutual coupling among the elements of each array. These isolating techniques enable minimal proximity between the arrays, achieving a center-to-center spacing of 28.88 mm (\u0000<inline-formula> <tex-math>$0.54lambda _{0}$ </tex-math></inline-formula>\u0000) and an edge-to-edge gap of less than 1 mm (\u0000<inline-formula> <tex-math>$lambda _{0}$ </tex-math></inline-formula>\u0000/50), theoretically approaching zero at the resonant frequency of 5.6 GHz. The conformal substrate of the cloak, produced using 3D printing technology, simplifies the fabrication process by covering only the top surface of the patches. The proposed design has been successfully fabricated and evaluated using detailed comparison metrics, including return loss, mutual coupling, radiation patterns, gain, and efficiency across cloaked and uncloaked configurations. The simulation and experimental results closely match, confirming that the cloaked antennas exhibit similar radiation performance to isolated elements.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 6","pages":"1691-1703"},"PeriodicalIF":3.5,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10638749","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1109/OJAP.2024.3445300
Jeff Frolik;Elsie Anthonio;Rye Fought;Tara Harte
Harmonic transponders are nonlinear, passive devices that typically receive an interrogation signal at one single frequency and reradiate harmonics. In this work, we propose leveraging the device’s nonlinearity by interrogating with two closely spaced signals and then measuring the second harmonics and nearby second and fourth intermodulation distortion products. Our results show that we are able to remotely determine the power incident at the device, over a 25 dB range and within ±1 dB, using only the relative ratios between these received components. This result has applications in characterizing the loss of unknown channels and in conducting over-the-air characterization of fully integrated transponders. We demonstrate this latter application.
谐波转发器是一种非线性、无源设备，通常接收单一频率的询问信号，并重新辐射谐波。在这项工作中，我们建议利用该设备的非线性特性，使用两个间隔很近的信号进行询问，然后测量二次谐波以及附近的二次和四次互调失真产物。我们的研究结果表明，只需利用这些接收分量之间的相对比率，我们就能在 25 dB 的范围内远程确定设备的入射功率，且误差不超过 ±1dB。这一结果可用于鉴定未知信道的损耗和对全集成转发器进行空中鉴定。我们演示了后一种应用。
{"title":"Ascertaining Operating Points of Harmonic Transponders Using Intermodulation Responses","authors":"Jeff Frolik;Elsie Anthonio;Rye Fought;Tara Harte","doi":"10.1109/OJAP.2024.3445300","DOIUrl":"10.1109/OJAP.2024.3445300","url":null,"abstract":"Harmonic transponders are nonlinear, passive devices that typically receive an interrogation signal at one single frequency and reradiate harmonics. In this work, we propose leveraging the device’s nonlinearity by interrogating with two closely spaced signals and then measuring the second harmonics and nearby second and fourth intermodulation distortion products. Our results show that we are able to remotely determine the power incident at the device, over a 25 dB range and within ±1 dB, using only the relative ratios between these received components. This result has applications in characterizing the loss of unknown channels and in conducting over-the-air characterization of fully integrated transponders. We demonstrate this latter application.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 5","pages":"1221-1228"},"PeriodicalIF":3.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10638145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.1109/OJAP.2024.3434008
Shu-Lin Chen;Dongze Zheng;Geng-Bo Wu;Y. Jay Guo;Ke Wu;Chi Hou Chan
Beyond 5G and 6G technologies mark a pivotal evolution in the telecommunications landscape. They are not only anticipated to deliver unprecedented speed and capacity but also to serve as critical enablers for a host of emerging technologies and applications, including joint communications and sensing, autonomous driving, augmented reality (AR), virtual reality (VR), and the burgeoning Internet of Things (IoT) [1] , [2] , [3] . As we transition into this new era, the expectations for system performance, reliability, and versatility are higher than ever before.
{"title":"Guest Editorial Special Section on Advanced Beam-Forming Antennas for Beyond 5G and 6G","authors":"Shu-Lin Chen;Dongze Zheng;Geng-Bo Wu;Y. Jay Guo;Ke Wu;Chi Hou Chan","doi":"10.1109/OJAP.2024.3434008","DOIUrl":"10.1109/OJAP.2024.3434008","url":null,"abstract":"Beyond 5G and 6G technologies mark a pivotal evolution in the telecommunications landscape. They are not only anticipated to deliver unprecedented speed and capacity but also to serve as critical enablers for a host of emerging technologies and applications, including joint communications and sensing, autonomous driving, augmented reality (AR), virtual reality (VR), and the burgeoning Internet of Things (IoT) \u0000<xref>[1]</xref>\u0000, \u0000<xref>[2]</xref>\u0000, \u0000<xref>[3]</xref>\u0000. As we transition into this new era, the expectations for system performance, reliability, and versatility are higher than ever before.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"5 4","pages":"803-809"},"PeriodicalIF":3.5,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10630582","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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