Image advertising is widely used by companies to advertise their products and increase awareness of their brands. With the constant development of image generation techniques, automatic compositing of advertisement images has also been widely studied. However, the existing algorithms cannot synthesise consistent-looking advertisement images for a given product. The key challenge is to stitch a given product into a scene that matches the style of the product while maintaining a consistent-looking. To solve this problem, this paper proposes a new two-stage automatic advertisement image generation model, called Advertisement Synthesis Network (ASNet), which explores a two-stage generation framework to synthesise consistent-looking product advertisement images. Specifically, ASNet first generates a preliminary target product scene using Pre-Synthesis and then extracts scene features using Pseudo-Target Object Encoder (PTOE) and true target features using Real Target Object Encoder (RTOE), respectively. Finally, we inject the acquired features into the pretrained diffusion model and reconstruct them in the preliminary generated target goods scene. Extensive experiments have shown that the method achieves better results in all three performance metrics related to the quality of the synthesised image compared to other methods. In addition, we have done a simple and preliminary study on the effect of synthetic advertisement images on real consumers’ purchase intention and brand perception. The results of the study show that the advertisement images synthesised by the model proposed in this paper have a positive impact on consumer purchase intention and brand perception.
{"title":"Advertisement Synthesis Network for Automatic Advertisement Image Synthesis","authors":"Qin Wu, Peizi Zhou","doi":"10.1155/2024/8030907","DOIUrl":"https://doi.org/10.1155/2024/8030907","url":null,"abstract":"Image advertising is widely used by companies to advertise their products and increase awareness of their brands. With the constant development of image generation techniques, automatic compositing of advertisement images has also been widely studied. However, the existing algorithms cannot synthesise consistent-looking advertisement images for a given product. The key challenge is to stitch a given product into a scene that matches the style of the product while maintaining a consistent-looking. To solve this problem, this paper proposes a new two-stage automatic advertisement image generation model, called Advertisement Synthesis Network (ASNet), which explores a two-stage generation framework to synthesise consistent-looking product advertisement images. Specifically, ASNet first generates a preliminary target product scene using Pre-Synthesis and then extracts scene features using Pseudo-Target Object Encoder (PTOE) and true target features using Real Target Object Encoder (RTOE), respectively. Finally, we inject the acquired features into the pretrained diffusion model and reconstruct them in the preliminary generated target goods scene. Extensive experiments have shown that the method achieves better results in all three performance metrics related to the quality of the synthesised image compared to other methods. In addition, we have done a simple and preliminary study on the effect of synthetic advertisement images on real consumers’ purchase intention and brand perception. The results of the study show that the advertisement images synthesised by the model proposed in this paper have a positive impact on consumer purchase intention and brand perception.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"23 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aiming at the application requirements of underwater cross-domain communication, based on the equivalent relationship between the rotating permanent magnet and the orthogonal time-varying current loop, this paper establishes an air-seawater-seabed three-layer medium model and analyzes the magnetic field distribution and propagation characteristics of the rotating permanent magnet-based mechanical antenna (RMBMA). Based on the electromagnetic field simulation software FEKO, the influence of vertical rotation and horizontal rotation of RMBMA on the radiation magnetic field is analyzed. The magnetic field distribution and magnetic field attenuation characteristics of RMBMA at different depths are obtained by simulation. The influence of RMBMA operating frequency and magnetic moment on the propagation characteristics is studied. The research shows that the horizontal rotation of the magnetic source is better than the vertical rotation in the long-distance underwater communication. When the magnetic source and the receiving point are close to the interface of the medium, the magnetic field strength and the propagation distance can be relatively increased. With appropriate frequency and magnetic moment, the magnetic field strength and communication distance can be further increased.
{"title":"Propagation Characteristics and Magnetic Field Distribution of Rotating Magnet-Based Mechanical Antenna in the Air-Seawater-Seabed Three-Layer Medium","authors":"S. P. Chen, Q. Zhou, J. Y. Zhang, S. Y. Wang","doi":"10.1155/2024/2023687","DOIUrl":"https://doi.org/10.1155/2024/2023687","url":null,"abstract":"Aiming at the application requirements of underwater cross-domain communication, based on the equivalent relationship between the rotating permanent magnet and the orthogonal time-varying current loop, this paper establishes an air-seawater-seabed three-layer medium model and analyzes the magnetic field distribution and propagation characteristics of the rotating permanent magnet-based mechanical antenna (RMBMA). Based on the electromagnetic field simulation software FEKO, the influence of vertical rotation and horizontal rotation of RMBMA on the radiation magnetic field is analyzed. The magnetic field distribution and magnetic field attenuation characteristics of RMBMA at different depths are obtained by simulation. The influence of RMBMA operating frequency and magnetic moment on the propagation characteristics is studied. The research shows that the horizontal rotation of the magnetic source is better than the vertical rotation in the long-distance underwater communication. When the magnetic source and the receiving point are close to the interface of the medium, the magnetic field strength and the propagation distance can be relatively increased. With appropriate frequency and magnetic moment, the magnetic field strength and communication distance can be further increased.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"22 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a triple-band, four-element antenna is designed for fifth-generation (5 G) terminals operating in LTE band 42 (3.4–3.6 GHz), LTE band 43 (3.6–3.8 GHz), and the new 5 G radio band (4.8–5.0 GHz). The proposed antenna array consists of two different types of antenna elements: a T-shaped element, which is connected to the feed line, and a C-shaped element, which is used to divide the bandwidth. The overall size of the proposed antenna element is only 10.5 mm × 5 mm. The multiantenna system has four antennas and is built on a 0.5-mm-thick Rogers 4003C substrate. The results for this antenna show a 10 dB measured bandwidth of 650 MHz at the center frequency of 3.6 GHz and 230 MHz at 4.9 GHz, a gain of more than 4 dBi, an isolation of more than 14 dB, and an overall radiation efficiency of more than 82%.
本文设计了一种三频四元件天线，适用于在 LTE 频段 42（3.4-3.6 GHz）、LTE 频段 43（3.6-3.8 GHz）和新的 5 G 无线电频段（4.8-5.0 GHz）工作的第五代 (5 G) 终端。拟议的天线阵列由两种不同类型的天线元件组成：一种是与馈电线相连的 T 形元件，另一种是用于划分带宽的 C 形元件。拟议的天线元件整体尺寸仅为 10.5 毫米 × 5 毫米。多天线系统有四个天线，建在 0.5 毫米厚的罗杰斯 4003C 衬底上。该天线的测量结果显示，中心频率为 3.6 GHz 时的 10 dB 测量带宽为 650 MHz，中心频率为 4.9 GHz 时的 10 dB 测量带宽为 230 MHz，增益超过 4 dBi，隔离度超过 14 dB，整体辐射效率超过 82%。
{"title":"Triple-Band MIMO Antenna for 5 G Terminals","authors":"Adnane Ghiat, Abdelwahed Tribak, Jaouad Terhzaz, Asmae Mimouni, Hanan Akhdar","doi":"10.1155/2024/6410202","DOIUrl":"https://doi.org/10.1155/2024/6410202","url":null,"abstract":"In this work, a triple-band, four-element antenna is designed for fifth-generation (5 G) terminals operating in LTE band 42 (3.4–3.6 GHz), LTE band 43 (3.6–3.8 GHz), and the new 5 G radio band (4.8–5.0 GHz). The proposed antenna array consists of two different types of antenna elements: a T-shaped element, which is connected to the feed line, and a C-shaped element, which is used to divide the bandwidth. The overall size of the proposed antenna element is only 10.5 mm × 5 mm. The multiantenna system has four antennas and is built on a 0.5-mm-thick Rogers 4003C substrate. The results for this antenna show a 10 dB measured bandwidth of 650 MHz at the center frequency of 3.6 GHz and 230 MHz at 4.9 GHz, a gain of more than 4 dBi, an isolation of more than 14 dB, and an overall radiation efficiency of more than 82%.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"48 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140114752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chuankui Shen, Zhengxing Wang, Liekun Yang, Fengcheng Mei, Terry Tao Ye
This paper presents, for the first time, the implementation of a pattern reconfigurable Yagi-Uda antenna utilizing radio frequency identification (RFID) technology for remote pattern control. The proposed scheme emphasizes the use of wireless communication instead of long metal cables, resulting in improved stability of the antenna’s pattern and return loss. Two low-power consumption single-pole-double-throw (SPDT) switches are employed on a passive resonator, enabling it to function as a director or reflector under the long-range control (up to 25 m) of an RFID reader. Measurement results demonstrate a −10 dB impedance bandwidth of 4.2% and a gain of 7 dBi at 2.41 GHz. The entire system operates with an ultra-low power consumption of 12 μW.
本文首次介绍了利用射频识别（RFID）技术实现模式可重构的八木宇田天线，用于远程模式控制。所提出的方案强调使用无线通信代替长金属电缆，从而提高了天线图案的稳定性和回波损耗。在无源谐振器上采用了两个低功耗单刀双掷（SPDT）开关，使其能够在 RFID 阅读器的远距离控制（最长 25 米）下充当导向器或反射器。测量结果表明，-10 dB 阻抗带宽为 4.2%，2.41 GHz 增益为 7 dBi。整个系统以 12 μW 的超低功耗运行。
{"title":"Wirelessly Pattern Reconfigurable Yagi Antenna Based on Radio Frequency Identification","authors":"Chuankui Shen, Zhengxing Wang, Liekun Yang, Fengcheng Mei, Terry Tao Ye","doi":"10.1155/2024/3660051","DOIUrl":"https://doi.org/10.1155/2024/3660051","url":null,"abstract":"This paper presents, for the first time, the implementation of a pattern reconfigurable Yagi-Uda antenna utilizing radio frequency identification (RFID) technology for remote pattern control. The proposed scheme emphasizes the use of wireless communication instead of long metal cables, resulting in improved stability of the antenna’s pattern and return loss. Two low-power consumption single-pole-double-throw (SPDT) switches are employed on a passive resonator, enabling it to function as a director or reflector under the long-range control (up to 25 m) of an RFID reader. Measurement results demonstrate a −10 dB impedance bandwidth of 4.2% and a gain of 7 dBi at 2.41 GHz. The entire system operates with an ultra-low power consumption of 12 <i>μ</i>W.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"66 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140076229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An analytical approach is presented that allows deriving an exact series-form representation for the flux linkage between two physically large concentric circular coils located on a lossy soil. The expression comes from a three-step analytical procedure. First, the integral expression for the flux linkage is converted into a double integral consisting of a finite and a semi-infinite integral. Next, the semi-infinite integral is recognized to be a well-known tabulated Sommerfeld integral, which may be analytically evaluated straightforwardly. Finally, applying Lommel’s expansion allows rewriting the remaining finite integral as a sum of elementary integrals amenable to analytical evaluation. As a result, the flux linkage between the two coils is given as a sum of spherical Hankel functions of the wavenumber in the air and in the ground, multiplied by a coefficient depending on the geometrical dimensions of the coils. The accuracy and robustness of the proposed formulation is tested by comparing its outcomes with those generated by numerical integration of the complete integral representation for the flux linkage and with the results provided by previous analytical approaches to the same problem. It is found that the use of the derived expression for the inductance makes it possible to obtain significant time savings as compared to numerical quadrature schemes.
{"title":"Evaluation of the Inductive Coupling between Coplanar Concentric Coils in the Presence of the Ground","authors":"Mauro Parise","doi":"10.1155/2024/6640727","DOIUrl":"https://doi.org/10.1155/2024/6640727","url":null,"abstract":"An analytical approach is presented that allows deriving an exact series-form representation for the flux linkage between two physically large concentric circular coils located on a lossy soil. The expression comes from a three-step analytical procedure. First, the integral expression for the flux linkage is converted into a double integral consisting of a finite and a semi-infinite integral. Next, the semi-infinite integral is recognized to be a well-known tabulated Sommerfeld integral, which may be analytically evaluated straightforwardly. Finally, applying Lommel’s expansion allows rewriting the remaining finite integral as a sum of elementary integrals amenable to analytical evaluation. As a result, the flux linkage between the two coils is given as a sum of spherical Hankel functions of the wavenumber in the air and in the ground, multiplied by a coefficient depending on the geometrical dimensions of the coils. The accuracy and robustness of the proposed formulation is tested by comparing its outcomes with those generated by numerical integration of the complete integral representation for the flux linkage and with the results provided by previous analytical approaches to the same problem. It is found that the use of the derived expression for the inductance makes it possible to obtain significant time savings as compared to numerical quadrature schemes.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"64 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140075268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bethelhem S. Shawel, Dereje H. Woldegebreal, Sofie Pollin
Providing global coverage for ubiquitous users is a key requirement of the fifth generation (5G) and beyond wireless technologies. This can be achieved by integrating airborne networks, such as unmanned aerial vehicles (UAVs) and satellite networks, with terrestrial networks. However, the deployment of airborne networks in a three-dimensional (3D) or volumetric space requires a new understanding of the propagation channel and its losses in both the areal and altitude dimensions. Despite significant research on radio environment map (REM) construction, much of it has been limited to two-dimensional (2D) contexts. This neglects the altitude-related characteristics of electromagnetic wave propagation and confines REMs to 2D formats, which limits the comprehensive and continuous visualization of propagation environment variation in spatial dimensions. This paper proposes a volumetric REM (VREM) construction approach to compute 3D propagation losses. The proposed approach addresses the limitations of existing approaches by learning the spatial correlation of wireless propagation channel characteristics and visualizing REM in areal and height/altitude dimensions using deep learning models. Specifically, the approach uses two deep learning-based models: volume-to-volume (Vol2Vol) VREM with 3D-generative adversarial networks and sliced VREM with altitude-aware spider-UNets. In both cases, knowledge of the propagation environment and transmitter locations in 3D space is used to capture the spatial and altitude dependency of the propagation channel’s characteristics. We developed the Addis dataset, a large REM dataset comprising 54,000 samples collected from the urban part of Addis Ababa, Ethiopia, to train the proposed models. Each sample of data comprises a 512-meter by 512-meter areal resolution with different 3D obstacles (buildings and terrain), 15 simulated propagation loss maps at every 3-meter altitude resolution, and 80 different 3D transmitter locations. The results of the training and testing of the proposed models reveal that the constructed VREMs are statistically comparable. In particular, the Vol2Vol approach has a minimum L1 loss of 0.01, which further decreases to 0.0084 as the line-of-sight (LoS) probability increases to 0.95.
{"title":"A Deep-Learning Approach to a Volumetric Radio Environment Map Construction for UAV-Assisted Networks","authors":"Bethelhem S. Shawel, Dereje H. Woldegebreal, Sofie Pollin","doi":"10.1155/2024/9062023","DOIUrl":"https://doi.org/10.1155/2024/9062023","url":null,"abstract":"Providing global coverage for ubiquitous users is a key requirement of the fifth generation (5G) and beyond wireless technologies. This can be achieved by integrating airborne networks, such as unmanned aerial vehicles (UAVs) and satellite networks, with terrestrial networks. However, the deployment of airborne networks in a three-dimensional (3D) or volumetric space requires a new understanding of the propagation channel and its losses in both the areal and altitude dimensions. Despite significant research on radio environment map (REM) construction, much of it has been limited to two-dimensional (2D) contexts. This neglects the altitude-related characteristics of electromagnetic wave propagation and confines REMs to 2D formats, which limits the comprehensive and continuous visualization of propagation environment variation in spatial dimensions. This paper proposes a volumetric REM (VREM) construction approach to compute 3D propagation losses. The proposed approach addresses the limitations of existing approaches by learning the spatial correlation of wireless propagation channel characteristics and visualizing REM in areal and height/altitude dimensions using deep learning models. Specifically, the approach uses two deep learning-based models: volume-to-volume (Vol2Vol) VREM with 3D-generative adversarial networks and sliced VREM with altitude-aware spider-UNets. In both cases, knowledge of the propagation environment and transmitter locations in 3D space is used to capture the spatial and altitude dependency of the propagation channel’s characteristics. We developed the Addis dataset, a large REM dataset comprising 54,000 samples collected from the urban part of Addis Ababa, Ethiopia, to train the proposed models. Each sample of data comprises a 512-meter by 512-meter areal resolution with different 3D obstacles (buildings and terrain), 15 simulated propagation loss maps at every 3-meter altitude resolution, and 80 different 3D transmitter locations. The results of the training and testing of the proposed models reveal that the constructed VREMs are statistically comparable. In particular, the Vol2Vol approach has a minimum L1 loss of 0.01, which further decreases to 0.0084 as the line-of-sight (LoS) probability increases to 0.95.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"118 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139968387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
İsmail Şişman, Tugba Haykir Ergin, Duygun Erol Barkana, Hüseyin Arda Ülkü
In this work, design of a five-element compact dual-polarization X band monopulse feed antenna using a 7.3 m Cassegrain-type reflector for Low Earth Orbit (LEO) satellite ground station is presented. The designed antenna has reached 32 dB/K G/T value, the side lobe level of the designed antenna is at the level of −24 dB, the crosspolarization value is −35 dB, and the port isolation value is below −29 dB in the 8–8.5 GHz frequency range. The antenna efficiency of the designed antenna is measured as 79.93%.
{"title":"Design and Realization of an X Band Monopulse Feed Antenna for Low Earth Orbit (LEO) Satellite Ground Station","authors":"İsmail Şişman, Tugba Haykir Ergin, Duygun Erol Barkana, Hüseyin Arda Ülkü","doi":"10.1155/2024/6659390","DOIUrl":"https://doi.org/10.1155/2024/6659390","url":null,"abstract":"In this work, design of a five-element compact dual-polarization <i>X</i> band monopulse feed antenna using a 7.3 m Cassegrain-type reflector for Low Earth Orbit (LEO) satellite ground station is presented. The designed antenna has reached 32 dB/K G/T value, the side lobe level of the designed antenna is at the level of −24 dB, the crosspolarization value is −35 dB, and the port isolation value is below −29 dB in the 8–8.5 GHz frequency range. The antenna efficiency of the designed antenna is measured as 79.93%.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"8 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139968644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xianggang Hu, Jiancang Su, Mingtao Zhang, Xi Li, Dingkun Ma, Jingang Gong, Kewei Cheng, Jia Liu, Jiande Zhang, Rui Li, Jie Cheng, Shaotong Wu
The equivalent isotropic radiated power (EIRP) of high-power microwave (HPM) systems is a core-evaluating indicator. In practical testing, locating a suitable test site for the far-field method becomes challenging due to the requisite antenna separation. The conventional near-field method necessitates the extraction of the antenna’s near-field distribution, resulting in a testing system of intricate complexity and diminished efficiency. Therefore, the traditional near-field method cannot be directly applied in HPM systems. In the present study, a new EIRP measurement method for HPM systems based on near-field testing was proposed. First, a monitoring antenna of a considerable scale is positioned within the near-field vicinity of the HPM antenna to capture radiation power, thereby deriving its equivalent input power. Subsequently, according to the EIRP definition and the measured gain of the HPM antenna, the EIRP of the HPM system can be acquired. Theoretical research on this measurement method was conducted, the electromagnetic simulation model was constructed, and a comprehensive analysis through simulation was undertaken. A measurement system was developed and verified experimentally. The results demonstrate the precision of this approach in determining the EIRP of the HPM system, thereby serving as a valuable tool for assessing the power-handling capability of the HPM antenna. The test error is ±0.5 dB.
{"title":"An EIRP Measurement Method of High-Power Microwave Systems Based on Near-Field Testing","authors":"Xianggang Hu, Jiancang Su, Mingtao Zhang, Xi Li, Dingkun Ma, Jingang Gong, Kewei Cheng, Jia Liu, Jiande Zhang, Rui Li, Jie Cheng, Shaotong Wu","doi":"10.1155/2024/2048009","DOIUrl":"https://doi.org/10.1155/2024/2048009","url":null,"abstract":"The equivalent isotropic radiated power (EIRP) of high-power microwave (HPM) systems is a core-evaluating indicator. In practical testing, locating a suitable test site for the far-field method becomes challenging due to the requisite antenna separation. The conventional near-field method necessitates the extraction of the antenna’s near-field distribution, resulting in a testing system of intricate complexity and diminished efficiency. Therefore, the traditional near-field method cannot be directly applied in HPM systems. In the present study, a new EIRP measurement method for HPM systems based on near-field testing was proposed. First, a monitoring antenna of a considerable scale is positioned within the near-field vicinity of the HPM antenna to capture radiation power, thereby deriving its equivalent input power. Subsequently, according to the EIRP definition and the measured gain of the HPM antenna, the EIRP of the HPM system can be acquired. Theoretical research on this measurement method was conducted, the electromagnetic simulation model was constructed, and a comprehensive analysis through simulation was undertaken. A measurement system was developed and verified experimentally. The results demonstrate the precision of this approach in determining the EIRP of the HPM system, thereby serving as a valuable tool for assessing the power-handling capability of the HPM antenna. The test error is ±0.5 dB.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"2 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139764838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The spectral smoothness properties of the low-frequency array of the square kilometer array (SKA), namely, SKA-Low, are an important issue for its scientific objectives to be attainable. A large array of 256 log-periodic dipole antennas, installed on top of a 42 m circular ground plane, will work as an SKA-Low station in the frequency range of 50–350 MHz. In this article, the ground plane-induced effects are examined in terms of antenna beam spectral characteristics, while different antenna placements are considered. Results are produced both at the isolated antenna and at the array level in the band 50–100 MHz, by employing an approximate method for the speeding-up of array simulations. We attempt to distinguish the ground plane effect from that of mutual coupling among antennas, which appears to be more severe at specific frequencies, using 2 figures of merit. The discrete Fourier transform (DFT) components of gain pattern ratios identify the fundamental spatial components of the ripple, while the envelope correlation coefficient quantifies the penalty to considering an infinite ground plane.
{"title":"Spectral Smoothness of Ground Plane Backed Log-Periodic Dipole Antennas for Radioastronomical Applications","authors":"Georgios Kyriakou, Pietro Bolli, Mirko Bercigli","doi":"10.1155/2024/1399941","DOIUrl":"https://doi.org/10.1155/2024/1399941","url":null,"abstract":"The spectral smoothness properties of the low-frequency array of the square kilometer array (SKA), namely, SKA-Low, are an important issue for its scientific objectives to be attainable. A large array of 256 log-periodic dipole antennas, installed on top of a 42 m circular ground plane, will work as an SKA-Low station in the frequency range of 50–350 MHz. In this article, the ground plane-induced effects are examined in terms of antenna beam spectral characteristics, while different antenna placements are considered. Results are produced both at the isolated antenna and at the array level in the band 50–100 MHz, by employing an approximate method for the speeding-up of array simulations. We attempt to distinguish the ground plane effect from that of mutual coupling among antennas, which appears to be more severe at specific frequencies, using 2 figures of merit. The discrete Fourier transform (DFT) components of gain pattern ratios identify the fundamental spatial components of the ripple, while the envelope correlation coefficient quantifies the penalty to considering an infinite ground plane.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"47 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139764888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a novel ultraminiaturized frequency selective surface (FSS) for L-band electromagnetic shielding applications. A basic square loop incorporated with folded arms in the top layer constructs the single-layer FSS design. Band-stop characteristics for the entire L-band operating frequency ranging from 1 GHz to 2 GHz are offered by the proposed design. An ultraminiaturized profile of 0.028λο × 0.028λο is achieved by the designed FSS, where λο corresponds to the lowest operating frequency, achieving at least 32.1% miniaturization when compared to the state-of-the-art FSS designs in the literature. Polarization insensitivity with a peak shielding effectiveness of 45.4 dB is manifested by the rotational symmetry of the proposed design. The proposed FSS exhibits excellent angular stability performance up to 80° with a frequency deviation of less than 1%. The equivalent circuit model helps to understand the working principle of the proposed FSS. The experimental results of the designed FSS prototype agree well with the simulation results. Hence, the proposed spatial filter is a suitable candidate for enhancing security in wireless communication at the carrier frequencies of GPS systems.
{"title":"A Novel Ultra-Miniaturized Angularly Stable Frequency Selective Surface for L-Band Shielding Applications","authors":"Malathi Kanagasabai, Shini Ramadoss, Lavanya Viswanathan, Gulam Nabi Alsath Mohammed, Shanmathi Shanmuganathan, Sandeep Kumar Palaniswamy","doi":"10.1155/2024/8777541","DOIUrl":"https://doi.org/10.1155/2024/8777541","url":null,"abstract":"This paper presents a novel ultraminiaturized frequency selective surface (FSS) for L-band electromagnetic shielding applications. A basic square loop incorporated with folded arms in the top layer constructs the single-layer FSS design. Band-stop characteristics for the entire L-band operating frequency ranging from 1 GHz to 2 GHz are offered by the proposed design. An ultraminiaturized profile of 0.028<i>λ</i><i>ο</i> × 0.028<i>λ</i><i>ο</i> is achieved by the designed FSS, where <i>λ</i><i>ο</i> corresponds to the lowest operating frequency, achieving at least 32.1% miniaturization when compared to the state-of-the-art FSS designs in the literature. Polarization insensitivity with a peak shielding effectiveness of 45.4 dB is manifested by the rotational symmetry of the proposed design. The proposed FSS exhibits excellent angular stability performance up to 80° with a frequency deviation of less than 1%. The equivalent circuit model helps to understand the working principle of the proposed FSS. The experimental results of the designed FSS prototype agree well with the simulation results. Hence, the proposed spatial filter is a suitable candidate for enhancing security in wireless communication at the carrier frequencies of GPS systems.","PeriodicalId":54392,"journal":{"name":"International Journal of Antennas and Propagation","volume":"12 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139764778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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