Pub Date : 2025-10-15DOI: 10.1109/OJAP.2025.3622330
Zhenjie Wen;Yuming Wu;Binchao Zhang;Weidong Hu
This paper presents an integrated shared-aperture transmitarray (TA) antenna that achieves a low radar cross section (RCS) at both in-band and out-of-band frequencies, while maintaining wideband beam convergence. The element employs a four-layer metallic structure: Cross-shaped patches and bent metallic strips are integrated on the top layer in a shared-aperture configuration, enabling independent reflection phase control across three distinct frequency bands; the middle two V-slot ground layers enable 1-bit transmission phase modulation via geometric rotation; and the bottom layer employs cross-shaped patches to ensure good radiation. Owing to the integrated design of the top-layer multi-band RCS reduction structures, the TA has a thickness of only $0.28lambda _{c}~(lambda _{c}$ denotes the wavelength corresponding to the center frequency). A $16times 16$ prototype is designed, fabricated, and measured. Measurement results demonstrate a peak gain of 20.46 dBi at 13.75 GHz with an aperture efficiency of 20.8% and 1-dB gain bandwidth of 8.96%. Furthermore, the proposed TA antenna achieves a 10 dB monostatic RCS reduction over bandwidths of 23.66% (8.2 to 10.4 GHz) and 12.69% (15.5 to 17.6 GHz), with a maximum in-band (12 to 14 GHz) reduction of 16 dB compared to the reference TA antenna.
{"title":"Integrated Shared-Aperture Transmitarray Antenna With In-Band and Out-of-Band RCS Reduction","authors":"Zhenjie Wen;Yuming Wu;Binchao Zhang;Weidong Hu","doi":"10.1109/OJAP.2025.3622330","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3622330","url":null,"abstract":"This paper presents an integrated shared-aperture transmitarray (TA) antenna that achieves a low radar cross section (RCS) at both in-band and out-of-band frequencies, while maintaining wideband beam convergence. The element employs a four-layer metallic structure: Cross-shaped patches and bent metallic strips are integrated on the top layer in a shared-aperture configuration, enabling independent reflection phase control across three distinct frequency bands; the middle two V-slot ground layers enable 1-bit transmission phase modulation via geometric rotation; and the bottom layer employs cross-shaped patches to ensure good radiation. Owing to the integrated design of the top-layer multi-band RCS reduction structures, the TA has a thickness of only <inline-formula> <tex-math>$0.28lambda _{c}~(lambda _{c}$ </tex-math></inline-formula> denotes the wavelength corresponding to the center frequency). A <inline-formula> <tex-math>$16times 16$ </tex-math></inline-formula> prototype is designed, fabricated, and measured. Measurement results demonstrate a peak gain of 20.46 dBi at 13.75 GHz with an aperture efficiency of 20.8% and 1-dB gain bandwidth of 8.96%. Furthermore, the proposed TA antenna achieves a 10 dB monostatic RCS reduction over bandwidths of 23.66% (8.2 to 10.4 GHz) and 12.69% (15.5 to 17.6 GHz), with a maximum in-band (12 to 14 GHz) reduction of 16 dB compared to the reference TA antenna.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2074-2082"},"PeriodicalIF":3.6,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11205179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584626","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 : 2025-10-08DOI: 10.1109/OJAP.2025.3619468
Abdullah Alshammari;Abdul Basir;Muhammad Zada;Syed Ahson Ali Shah;Amjad Iqbal;Ismail Ben Mabrouk
This paper presents a novel duplex implantable antenna for simultaneous wireless power transfer and data telemetry in wireless capsule endoscopy (WCE) applications. The proposed antenna operates at 1.8 GHz (wireless power transfer) when Port-1 is excited and 2.4 GHz (data telemetry) when Port-2 is excited. The antenna’s performance has been evaluated within a simulated human stomach phantom to closely mimic real-world implantation scenarios. Shorting pins, semi-circular and open-end slots techniques are used to make the antenna smaller, resulting in a compact volume of 8.17 mm3. Slots of different lengths on both patches generate different resonant frequencies. A rectangular slot with a width of 0.4 mm and a length of 6.3 mm is introduced in the center of the ground plane, achieving an isolation level better than 28 dB. The antenna provides nearly omnidirectional patterns at both frequencies with gain values of −24.7 dBi at 1.8 GHz and −23.9 dBi at 2.4 GHz. Link budget and specific absorption rate (SAR) are investigated. The fabricated prototype is tested in minced pork meat, with good agreement between experimental and simulation results. The antenna system has a compact size, low coupling levels, and can simultaneously transmit data and receive power without the need of a multiplexer. With these attributes, the proposed design is a promising candidate for WCE devices requiring simultaneous data communication and power reception.
{"title":"Miniaturized Duplex Implantable Antenna for Wireless Data Communication and Power Transfer","authors":"Abdullah Alshammari;Abdul Basir;Muhammad Zada;Syed Ahson Ali Shah;Amjad Iqbal;Ismail Ben Mabrouk","doi":"10.1109/OJAP.2025.3619468","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3619468","url":null,"abstract":"This paper presents a novel duplex implantable antenna for simultaneous wireless power transfer and data telemetry in wireless capsule endoscopy (WCE) applications. The proposed antenna operates at 1.8 GHz (wireless power transfer) when Port-1 is excited and 2.4 GHz (data telemetry) when Port-2 is excited. The antenna’s performance has been evaluated within a simulated human stomach phantom to closely mimic real-world implantation scenarios. Shorting pins, semi-circular and open-end slots techniques are used to make the antenna smaller, resulting in a compact volume of 8.17 mm3. Slots of different lengths on both patches generate different resonant frequencies. A rectangular slot with a width of 0.4 mm and a length of 6.3 mm is introduced in the center of the ground plane, achieving an isolation level better than 28 dB. The antenna provides nearly omnidirectional patterns at both frequencies with gain values of −24.7 dBi at 1.8 GHz and −23.9 dBi at 2.4 GHz. Link budget and specific absorption rate (SAR) are investigated. The fabricated prototype is tested in minced pork meat, with good agreement between experimental and simulation results. The antenna system has a compact size, low coupling levels, and can simultaneously transmit data and receive power without the need of a multiplexer. With these attributes, the proposed design is a promising candidate for WCE devices requiring simultaneous data communication and power reception.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2062-2073"},"PeriodicalIF":3.6,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11196054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584650","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 : 2025-10-07DOI: 10.1109/OJAP.2025.3618386
Francesca Venneri;Sandra Costanzo
A single-layer reflectarray configuration is investigated for dual-polarization operation at 5G millimeter wave (mmWave) frequencies. The proposed reflectarray cell is designed as a viable solution for passive reflecting surfaces to enhance 5G network coverage. It consists of two alternating pairs of miniaturized linearly polarized patches, each operating at the same resonant frequency but rotated by 90° to enable dual polarization. This design allows independent phase tuning for each polarization, features an ultra-thin structure ($sim 0.0237lambda $ at 28 GHz), and maintains compact cell dimensions ($sim 0.4lambda $ at f=28 GHz), ensuring seamless integration and conformability to the support surface while preserving beam-focusing capabilities at large scan angles. A 28 GHz reflectarray-based passive reflecting surface is designed and experimentally validated as a solution for 5G blind spot scenarios, demonstrating independent backscatter for each polarization and enabling dual-coverage, dual-polarized operation. This independent dual-polarization control enables practical benefits, such as improved link reliability in NLoS (Non-Line-of-Sight) environments, simultaneous coverage of distinct zones, and potential support for multiple service providers to share the same frequency, thus highlighting the versatility and practical relevance of the proposed configuration. Due to its compactness, polarization flexibility, and cost-effectiveness, this configuration is a promising candidate for next-generation mmWave telecommunications, particularly in dense urban environments.
{"title":"Dual Polarized Dual Coverage Reflectarray-Based Passive Reflecting Surface for Next-Generation Networks","authors":"Francesca Venneri;Sandra Costanzo","doi":"10.1109/OJAP.2025.3618386","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3618386","url":null,"abstract":"A single-layer reflectarray configuration is investigated for dual-polarization operation at 5G millimeter wave (mmWave) frequencies. The proposed reflectarray cell is designed as a viable solution for passive reflecting surfaces to enhance 5G network coverage. It consists of two alternating pairs of miniaturized linearly polarized patches, each operating at the same resonant frequency but rotated by 90° to enable dual polarization. This design allows independent phase tuning for each polarization, features an ultra-thin structure (<inline-formula> <tex-math>$sim 0.0237lambda $ </tex-math></inline-formula> at 28 GHz), and maintains compact cell dimensions (<inline-formula> <tex-math>$sim 0.4lambda $ </tex-math></inline-formula> at f=28 GHz), ensuring seamless integration and conformability to the support surface while preserving beam-focusing capabilities at large scan angles. A 28 GHz reflectarray-based passive reflecting surface is designed and experimentally validated as a solution for 5G blind spot scenarios, demonstrating independent backscatter for each polarization and enabling dual-coverage, dual-polarized operation. This independent dual-polarization control enables practical benefits, such as improved link reliability in NLoS (Non-Line-of-Sight) environments, simultaneous coverage of distinct zones, and potential support for multiple service providers to share the same frequency, thus highlighting the versatility and practical relevance of the proposed configuration. Due to its compactness, polarization flexibility, and cost-effectiveness, this configuration is a promising candidate for next-generation mmWave telecommunications, particularly in dense urban environments.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2050-2061"},"PeriodicalIF":3.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11195127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584619","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 : 2025-09-29DOI: 10.1109/OJAP.2025.3615846
Zi Long Ma;Yang Li Geng
This paper presents a triple-band shared-aperture antenna operating in the S-, K-, and Ka-bands. The antenna is based on a modified transmitarray antenna (TA) where a $2times 2$ monopole array (MA) is integrated into its transmitting surface (TS). In the S-band, the proposed antenna functions as the MA, while in the K- and Ka-bands, it operates as a dual-band TA. To tightly integrate the two kinds of antennas, the reflector of the MA is redesigned as a high-pass frequency selective surface (FSS), which behaves like a conventional metal sheet in the S-band and allows K- and Ka-band waves to pass through and illuminate the TS. For dual-band operation of the TA, the TS employs a multi-layered unit cell (UC), where two rectangular slots of different lengths are arranged in an interlaced form. By adjusting the slot lengths, independent phase shifts covering 360° can be achieved for both bands. The proposed antenna features a compact size and high gain across all three bands. In the K- and Ka-bands, it eliminates the need for a feeding network due to the spatial feeding architecture of the TA, resulting in very low feeding loss. As a proof of the concept, a prototype is fabricated and measured. The experimental results show peak gain of 11.5 dBi, 17.9 dBi, and 21.3 dBi in the S-, K-, and Ka-bands, respectively. Beam scanning ranges of ±27° and ±25° are achieved in the K- and Ka-bands, respectively. The proposed antenna could be a promising candidate for multi-band communications.
{"title":"A S/K/Ka Triple-Band Shared-Aperture Antenna Hybridizing Monopole Array and Transmitarray","authors":"Zi Long Ma;Yang Li Geng","doi":"10.1109/OJAP.2025.3615846","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3615846","url":null,"abstract":"This paper presents a triple-band shared-aperture antenna operating in the S-, K-, and Ka-bands. The antenna is based on a modified transmitarray antenna (TA) where a <inline-formula> <tex-math>$2times 2$ </tex-math></inline-formula> monopole array (MA) is integrated into its transmitting surface (TS). In the S-band, the proposed antenna functions as the MA, while in the K- and Ka-bands, it operates as a dual-band TA. To tightly integrate the two kinds of antennas, the reflector of the MA is redesigned as a high-pass frequency selective surface (FSS), which behaves like a conventional metal sheet in the S-band and allows K- and Ka-band waves to pass through and illuminate the TS. For dual-band operation of the TA, the TS employs a multi-layered unit cell (UC), where two rectangular slots of different lengths are arranged in an interlaced form. By adjusting the slot lengths, independent phase shifts covering 360° can be achieved for both bands. The proposed antenna features a compact size and high gain across all three bands. In the K- and Ka-bands, it eliminates the need for a feeding network due to the spatial feeding architecture of the TA, resulting in very low feeding loss. As a proof of the concept, a prototype is fabricated and measured. The experimental results show peak gain of 11.5 dBi, 17.9 dBi, and 21.3 dBi in the S-, K-, and Ka-bands, respectively. Beam scanning ranges of ±27° and ±25° are achieved in the K- and Ka-bands, respectively. The proposed antenna could be a promising candidate for multi-band communications.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2040-2049"},"PeriodicalIF":3.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11184505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584635","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 : 2025-09-22DOI: 10.1109/OJAP.2025.3613605
Nick Van Rooijen;Maria Alonso-delPino;Juan Bueno;Nuria Llombart
This work presents an electrically-small lens that has been redesigned towards a flat interface. This way, the lens is easier to integrated, compared to an earlier introduced spherical core-shell lens concept. The lens is created from a single dielectric host material by conformally machining holes into the material. In this process, two artificial dielectric layers are created; The first layer is used for anti-reflection purposes, whereas the second is used to convert the spherical interface to a flat interface. The two layers enable the use of holes with lower aspect ratio drilling, compared to classical gradient-index lenses. The lens is designed to operate in the 140-170 GHz bandwidth, and a prototype with height of only 2.2 mm and diameter of 6.6 mm was fabricated and characterize. The prototype is small enough to fit in many integrated circuit packages. The flat lens was compared to a non-flat core lens in terms of pattern quality, return loss and dielectric loss, with only negligible performance degradation.
{"title":"Flat Lens-in-Package Architecture Using Multi-Axis Machining in D-Band","authors":"Nick Van Rooijen;Maria Alonso-delPino;Juan Bueno;Nuria Llombart","doi":"10.1109/OJAP.2025.3613605","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3613605","url":null,"abstract":"This work presents an electrically-small lens that has been redesigned towards a flat interface. This way, the lens is easier to integrated, compared to an earlier introduced spherical core-shell lens concept. The lens is created from a single dielectric host material by conformally machining holes into the material. In this process, two artificial dielectric layers are created; The first layer is used for anti-reflection purposes, whereas the second is used to convert the spherical interface to a flat interface. The two layers enable the use of holes with lower aspect ratio drilling, compared to classical gradient-index lenses. The lens is designed to operate in the 140-170 GHz bandwidth, and a prototype with height of only 2.2 mm and diameter of 6.6 mm was fabricated and characterize. The prototype is small enough to fit in many integrated circuit packages. The flat lens was compared to a non-flat core lens in terms of pattern quality, return loss and dielectric loss, with only negligible performance degradation.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2032-2039"},"PeriodicalIF":3.6,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11175571","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584620","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 : 2025-09-22DOI: 10.1109/OJAP.2025.3612587
Li Wei;Wanchen Yang;Guoping Tan;Chujun Liang;Zhongying Wang;Wenquan Che
The manuscript presents a $4times 4$ Sub-6GHz heterogeneous metasurface-based array integrated with $8times 8$ millimeter-wave (mmW) phased array within same aperture. Firstly, two heterogeneous Sub-6GHz antenna elements are designed based on a square ring metasurface (SRMS) and an overlapped metasurface (OLMS), respectively. The SRMS-based antenna is stacked above the $8times 8$ mmW array without occupying additional space, while the feeding networks of the Sub-6GHz and mmW antennas are also integrated together in one package using the low-temperature-cofired ceramic (LTCC) technology. In addition, the OLMS-based antenna offers the same bandwidth and wider beam than the former. Through near-field analysis of the array, phase differences resulting from the height variation among the heterogeneous elements have been compensated. Secondly, the heterogeneous antennas are constructed to a $4times 4$ Sub-6GHz array, with two $8times 8$ mmW arrays integrated beneath the SRMS-based elements. To ensure the scanning performance of the heterogeneous Sub-6GHz array, several dummy metasurface (MS) are loaded at sides to enhance radiation while increasing the scanning angle. Besides, a $pi $ -shaped decoupling paths are loaded between adjacent elements, which can cancel the inherent couplings with scanning efficiency increasing. Finally, the proposed heterogeneous array is fabricated and measured. The $4times 4$ Sub-6GHz heterogeneous array integrating with the mmW arrays can operate in 3.3-3.6GHz and 24.25-29.5GHz. The array can achieve a wide-angle scanning range from –55° to 55° with high isolation of over 20dB in both bands. Compared with other works, it not only realizes aperture-shared integration of Sub-6GHz phased array and mmW phased array, but also ensure dual-band wide-angle scanning, which can be potentially applied in future multi-band base-station antennas.
{"title":"Dual-Band and Dual Wide-Angle Scanning Heterogeneous Metasurface-Based Antenna Array in Large Frequency Ratio Integrating With Millimeter-Wave Phased Arrays in Same Aperture","authors":"Li Wei;Wanchen Yang;Guoping Tan;Chujun Liang;Zhongying Wang;Wenquan Che","doi":"10.1109/OJAP.2025.3612587","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3612587","url":null,"abstract":"The manuscript presents a <inline-formula> <tex-math>$4times 4$ </tex-math></inline-formula> Sub-6GHz heterogeneous metasurface-based array integrated with <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> millimeter-wave (mmW) phased array within same aperture. Firstly, two heterogeneous Sub-6GHz antenna elements are designed based on a square ring metasurface (SRMS) and an overlapped metasurface (OLMS), respectively. The SRMS-based antenna is stacked above the <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> mmW array without occupying additional space, while the feeding networks of the Sub-6GHz and mmW antennas are also integrated together in one package using the low-temperature-cofired ceramic (LTCC) technology. In addition, the OLMS-based antenna offers the same bandwidth and wider beam than the former. Through near-field analysis of the array, phase differences resulting from the height variation among the heterogeneous elements have been compensated. Secondly, the heterogeneous antennas are constructed to a <inline-formula> <tex-math>$4times 4$ </tex-math></inline-formula> Sub-6GHz array, with two <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> mmW arrays integrated beneath the SRMS-based elements. To ensure the scanning performance of the heterogeneous Sub-6GHz array, several dummy metasurface (MS) are loaded at sides to enhance radiation while increasing the scanning angle. Besides, a <inline-formula> <tex-math>$pi $ </tex-math></inline-formula>-shaped decoupling paths are loaded between adjacent elements, which can cancel the inherent couplings with scanning efficiency increasing. Finally, the proposed heterogeneous array is fabricated and measured. The <inline-formula> <tex-math>$4times 4$ </tex-math></inline-formula> Sub-6GHz heterogeneous array integrating with the mmW arrays can operate in 3.3-3.6GHz and 24.25-29.5GHz. The array can achieve a wide-angle scanning range from –55° to 55° with high isolation of over 20dB in both bands. Compared with other works, it not only realizes aperture-shared integration of Sub-6GHz phased array and mmW phased array, but also ensure dual-band wide-angle scanning, which can be potentially applied in future multi-band base-station antennas.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2020-2031"},"PeriodicalIF":3.6,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11174997","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584629","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 : 2025-09-18DOI: 10.1109/OJAP.2025.3611407
Zhuang Qu;Song Zha;Jihong Zhang;Ming Xu;Zhengwei Liu;Peiguo Liu
This paper proposed a Cassegrain antenna with a field-controlled reconfigurable subreflector for high-intensity radiation fields (HIRF) protection. By replacing the rotating hyperboloid subreflector with a field-controlled reconfigurable metasurface, the antenna can adaptively change its gain based on the incident electromagnetic field intensity. The proposed reconfigurable metasurface consists of 97 unit cells, each unit cell with a thickness of 4 mm and equipped with four diodes. The simulation and measurement have demonstrated that under low-intensity fields, the gain of the proposed antenna reaches 27.4 dBi at 9.3 GHz, which is only 0.3 dB less than the normal hyperboloid subreflector antenna. In HIRF, the gain of the proposed antenna decreases to 8.9 dBi, below the level of the feed.
{"title":"A Cassegrain Antenna With Field-Controlled Reconfigurable Subreflector for HIRF Protection","authors":"Zhuang Qu;Song Zha;Jihong Zhang;Ming Xu;Zhengwei Liu;Peiguo Liu","doi":"10.1109/OJAP.2025.3611407","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3611407","url":null,"abstract":"This paper proposed a Cassegrain antenna with a field-controlled reconfigurable subreflector for high-intensity radiation fields (HIRF) protection. By replacing the rotating hyperboloid subreflector with a field-controlled reconfigurable metasurface, the antenna can adaptively change its gain based on the incident electromagnetic field intensity. The proposed reconfigurable metasurface consists of 97 unit cells, each unit cell with a thickness of 4 mm and equipped with four diodes. The simulation and measurement have demonstrated that under low-intensity fields, the gain of the proposed antenna reaches 27.4 dBi at 9.3 GHz, which is only 0.3 dB less than the normal hyperboloid subreflector antenna. In HIRF, the gain of the proposed antenna decreases to 8.9 dBi, below the level of the feed.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"1980-1988"},"PeriodicalIF":3.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11172697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584630","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 : 2025-09-18DOI: 10.1109/OJAP.2025.3611662
Amine Essa;Eqab Almajali;Feras Barneih;Jawad Yousaf;Rony E. Amaya;Soliman Mahmoud
This work presents the development of a new, compact, two-port ultra-wideband implantable antenna with low sensitivity to implanting tissue and depth for energy harvesting applications in implantable medical devices (IMD). The proposed antenna features two compact radiating elements, operating at a center frequency of 2.45 GHz and occupying a very compact volume of 22.1 mm3 ($7.25times 6times 0$ .508 mm3). Miniaturization techniques such as meandered line slots, Defected Ground Structure (DGS), and shorting via were utilized to achieve this compactness. The stable performance of the antenna versus the implantation depth is established numerically and experimentally by considering both shallow and deep implantation depths. The antenna was implanted in a meat phantom and the results revealed wideband performance with measured bandwidths of 80.5% ($1.38~sim ~3$ .24 GHz) and 32.6% ($2.08~sim ~2$ .89 GHz) for Port-1 and Port-2, respectively. This ultra-wideband performance is shown to be effective in reducing the antenna’s sensitivity to the different types and depths of human biological tissues. Finally, the performance of the proposed implantable antenna has been successfully examined as part of a complete Wireless Power Transfer (WPT) system developed to improve Power Transfer Efficiency (PTE). The results show the superiority of the proposed two-port implantable antenna in improving PTE compared to the typical single-port implantable antennas.
{"title":"A Compact Tissue-Insensitive Ultra-Wideband Implantable Antenna for Wireless Power Transfer in Implantable Medical Devices","authors":"Amine Essa;Eqab Almajali;Feras Barneih;Jawad Yousaf;Rony E. Amaya;Soliman Mahmoud","doi":"10.1109/OJAP.2025.3611662","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3611662","url":null,"abstract":"This work presents the development of a new, compact, two-port ultra-wideband implantable antenna with low sensitivity to implanting tissue and depth for energy harvesting applications in implantable medical devices (IMD). The proposed antenna features two compact radiating elements, operating at a center frequency of 2.45 GHz and occupying a very compact volume of 22.1 mm3 (<inline-formula> <tex-math>$7.25times 6times 0$ </tex-math></inline-formula>.508 mm3). Miniaturization techniques such as meandered line slots, Defected Ground Structure (DGS), and shorting via were utilized to achieve this compactness. The stable performance of the antenna versus the implantation depth is established numerically and experimentally by considering both shallow and deep implantation depths. The antenna was implanted in a meat phantom and the results revealed wideband performance with measured bandwidths of 80.5% (<inline-formula> <tex-math>$1.38~sim ~3$ </tex-math></inline-formula>.24 GHz) and 32.6% (<inline-formula> <tex-math>$2.08~sim ~2$ </tex-math></inline-formula>.89 GHz) for Port-1 and Port-2, respectively. This ultra-wideband performance is shown to be effective in reducing the antenna’s sensitivity to the different types and depths of human biological tissues. Finally, the performance of the proposed implantable antenna has been successfully examined as part of a complete Wireless Power Transfer (WPT) system developed to improve Power Transfer Efficiency (PTE). The results show the superiority of the proposed two-port implantable antenna in improving PTE compared to the typical single-port implantable antennas.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"1989-2006"},"PeriodicalIF":3.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11172313","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584624","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}
Although finite difference time-domain (FDTD) algorithms are potentially applicable to broadband wave propagation and radiation problems, various problems related to the absorbing boundary condition and complex structural meshing limit the accuracy of FDTD calculations. This paper develops an unconditionally stable Crank–Nicolson factorization-splitting (CNFS) algorithm with a higher-order perfectly matched layer (PML) scheme. The higher-order PML is formulated through the matrix exponential (ME) method, which requires fewer operators and less manipulation than the existing implementation. To analyze the fine details and curves, the sub-gridding technique is modified through the unconditionally stable CNFS algorithm. Introducing nonuniform mesh sizes inside the computational domains improves the efficiency without degrading the computational accuracy. The effectiveness of the algorithm is evaluated in wave radiation and propagation problems, including radar cross-section evaluation and antenna design. The numerical and experimental results favorably agree, confirming the effectiveness of the sub-gridding technique and ME-PML based on the CNFS algorithm.
{"title":"Higher-Order Matrix Exponential Perfectly Matched Layer Scheme With Sub-Gridding Technique Based on the Factorization Approximate Crank–Nicolson Algorithm","authors":"Weikang Si;Hao Lei;Haolin Jiang;Yongjun Xie;Weilong Wang;Peiyu Wu","doi":"10.1109/OJAP.2025.3611666","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3611666","url":null,"abstract":"Although finite difference time-domain (FDTD) algorithms are potentially applicable to broadband wave propagation and radiation problems, various problems related to the absorbing boundary condition and complex structural meshing limit the accuracy of FDTD calculations. This paper develops an unconditionally stable Crank–Nicolson factorization-splitting (CNFS) algorithm with a higher-order perfectly matched layer (PML) scheme. The higher-order PML is formulated through the matrix exponential (ME) method, which requires fewer operators and less manipulation than the existing implementation. To analyze the fine details and curves, the sub-gridding technique is modified through the unconditionally stable CNFS algorithm. Introducing nonuniform mesh sizes inside the computational domains improves the efficiency without degrading the computational accuracy. The effectiveness of the algorithm is evaluated in wave radiation and propagation problems, including radar cross-section evaluation and antenna design. The numerical and experimental results favorably agree, confirming the effectiveness of the sub-gridding technique and ME-PML based on the CNFS algorithm.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"2007-2019"},"PeriodicalIF":3.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11172344","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584625","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 : 2025-09-17DOI: 10.1109/OJAP.2025.3611033
Guo-Ping Gao;Wen-Di Guo;Xuan Wang;Jun-Jie Xia;Bin Hu
Wearable antennas are essential for Internet of Things (IoT) devices, as their performance critically affects system reliability and functionality. Therefore, this paper proposes an omni-/unidirectional dual-mode, dual-polarized circular patch wearable antenna. The antenna employs a single-layer dielectric substrate made of felt, which is low-cost and easy to fabricate. It operates in the 2.45 GHz and 5.8 GHz ISM frequency bands, achieving unidirectional and omnidirectional radiation patterns, respectively. At 2.45 GHz, circular polarization (CP) is realized by etching an oblique slot at the center of the circular patch to periodically excite the TM11 mode. At 5.8 GHz, orthogonal slots are etched on the circular patch to adjust the resonant frequency and impedance matching of the TM02 mode, thereby achieving linear polarization (LP). The measured impedance bandwidths of the antenna in CP and LP modes are 160 MHz (2.37 GHz to 2.53 GHz) and 270 MHz (5.68 GHz to 5.95 GHz), respectively. Furthermore, the antenna exhibits favorable performance under different bending conditions and when in proximity to human tissue. Meanwhile, its low specific absorption rate (SAR) value indicates that the safety of wearing the antenna on the human body is guaranteed. CP can enhance signal stability and reduce interference in wireless body area network (WBAN) communication, particularly in scenarios involving frequent human movements. In contrast, the 5.8 GHz band requires omnidirectional radiation to achieve wide coverage and reduce back radiation, thus meeting the safety and comfort requirements of wearable devices.
{"title":"Omni-/Unidirectional Dual-Mode Dual-Polarized Wearable Antenna for IoT Applications","authors":"Guo-Ping Gao;Wen-Di Guo;Xuan Wang;Jun-Jie Xia;Bin Hu","doi":"10.1109/OJAP.2025.3611033","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3611033","url":null,"abstract":"Wearable antennas are essential for Internet of Things (IoT) devices, as their performance critically affects system reliability and functionality. Therefore, this paper proposes an omni-/unidirectional dual-mode, dual-polarized circular patch wearable antenna. The antenna employs a single-layer dielectric substrate made of felt, which is low-cost and easy to fabricate. It operates in the 2.45 GHz and 5.8 GHz ISM frequency bands, achieving unidirectional and omnidirectional radiation patterns, respectively. At 2.45 GHz, circular polarization (CP) is realized by etching an oblique slot at the center of the circular patch to periodically excite the TM11 mode. At 5.8 GHz, orthogonal slots are etched on the circular patch to adjust the resonant frequency and impedance matching of the TM02 mode, thereby achieving linear polarization (LP). The measured impedance bandwidths of the antenna in CP and LP modes are 160 MHz (2.37 GHz to 2.53 GHz) and 270 MHz (5.68 GHz to 5.95 GHz), respectively. Furthermore, the antenna exhibits favorable performance under different bending conditions and when in proximity to human tissue. Meanwhile, its low specific absorption rate (SAR) value indicates that the safety of wearing the antenna on the human body is guaranteed. CP can enhance signal stability and reduce interference in wireless body area network (WBAN) communication, particularly in scenarios involving frequent human movements. In contrast, the 5.8 GHz band requires omnidirectional radiation to achieve wide coverage and reduce back radiation, thus meeting the safety and comfort requirements of wearable devices.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"6 6","pages":"1972-1979"},"PeriodicalIF":3.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11168821","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584665","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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