Article
Chemistry, Analytical
Chunxi Liu, Dongliang Peng, Zhikun Chen, Yong Wu, Binan Wang
Summary: The reconfigurable antenna array direction finding system allows for dynamic loading of antennas using microwave switches to conduct fast DOA searches, addressing issues such as signal crosstalk in traditional systems. An improved TD search algorithm enhances system efficiency, with the system's effectiveness proven through real experiments and the advantages verified through detailed simulations.
Article
Engineering, Electrical & Electronic
Weihua Tan, Xiaoyong Shan, Zhongxiang Shen
Summary: This communication presents a low-profile ultrawideband circularly polarized antenna made of Rogers RT/Duroid 5880 PCB board, which demonstrates a wide 10 dB return loss bandwidth and is suitable for indoor positioning applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Ruyu Ma, Nader Behdad
Summary: This paper presents a platform-based high-frequency antenna array that enhances bandwidth and direction-finding accuracy. By exciting characteristic modes of the platform, the array overcomes the limitations of practical DF arrays on moving platforms. Simulation and testing results demonstrate improved performance compared to standalone arrays.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Wenrui Zheng, Hui Li, Guolin Liu
Summary: In this letter, an efficient and practical method for designing smartwatch antennas with circular polarization and multiband operation is proposed. By varying the impedance matrix using reactance, the total currents of the antenna and far-field properties are optimized. The optimized antenna prototype shows good performance in terms of axial ratio and wide bandwidths. This simple and practical implementation is highly attractive for commercial smartwatch antennas.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Kang Ding, Yujian Li, Yanjie Wu
Summary: A broadband circularly polarized magnetoelectric dipole antenna loaded with a parasitic loop is presented in this study. By introducing a parasitic loop coplanar with the horizontal patch, additional circular polarization modes are generated, resulting in an enhanced 3 dB axial-ratio bandwidth. Measurement results show that the proposed antenna exhibits a wide impedance bandwidth and 3 dB axial-ratio bandwidth, as well as flat gain and stable unidirectional radiation patterns within the designated frequency band.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Heesu Wang, Ikmo Park
Summary: In this work, a novel circularly polarized dipole antenna fed by modified quadrature hybrid couplers is proposed. The antenna achieves wide axial ratio bandwidth and stable radiation patterns by using a modified QHC with minimal variation in the phase and amplitude difference between the output ports over a wide frequency range. The antenna demonstrates good performance parameters including impedance bandwidth, AR bandwidth, and relatively small size.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Qian-Qian Li, Hai-Feng Zhang
Summary: In this article, a chiral metastructure absorber (CMMA) is combined with a circularly polarized (CP) antenna array based on a sequential-phase feed network to improve the axial ratio beamwidth (ARBW) by absorbing cross-polarization. The proposed CMMA unit achieves good circular dichroism at 4.9-5.2 GHz, improving the ARBW of the antenna in this frequency band. The 3-D form of the feed network reduces coupling with the radiation patches, resulting in higher gain. The measured impedance bandwidth is 80% (2.81-6.81 GHz), AR bandwidth is 70.8% (3.68-7.22 GHz), and peak gain is 15.28 dBi.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Yaowei Hou, Yueping Zhang, Junfa Mao
Summary: This letter presents a differential wideband circularly polarized laminated resonator antenna fed by quadruple L-shaped probes. By using a pair of 90 degrees power dividers as the feed network and supplying them with differential signals, the antenna can generate circular polarization. Experimental results show that the proposed antenna achieves a wide effective CP bandwidth of 52% and stable gain and radiation patterns within the usable bandwidth.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Wei He, Yejun He, Yin Li, Sai-Wai Wong, Lei Zhu
Summary: The compact ultrawideband circularly polarized antenna array proposed in this study can effectively enhance the operating bandwidth and reduce size, exhibiting excellent CP characteristics.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Changwu Tong, Hauke Ingolf Kremer, Nan Yang, Kwok Wa Leung
Summary: Using dielectric vias, a compact and wide-band circularly polarized dielectric resonator antenna is proposed. The use of high dielectric constant in the vias helps in reducing the size of the antenna. By redistributing the resonant frequencies, the antenna achieves wide impedance and axial ratio bandwidths. The antenna is fabricated using standard PCB process.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Weiwen Li, Guang Yang, Qiuhao Li, Yanhui Liu, Qiubo Ye, Qing Huo Liu
Summary: This study explores the generation of wideband circularly polarized radiation waves using a single feeding structure on an annular ring conductor patch. By implementing characteristic mode analysis and capacitive coupling effects, the proposed antenna successfully operates in the 2.4 GHz band, showing impedance and axial ratio bandwidths of 26% and 10.6% respectively, while also exhibiting good structural tolerance capability.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Yang Hu, Yong Mei Pan, Mei Di Yang
Summary: This study investigates a circularly polarized MIMO antenna consisting of two identical DRAs, which effectively increase isolation between them and allow for simultaneous operation. By using metal strips to change the E-field rotation direction, the polarization properties of the passive DRAs are reversed compared to the active DRAs. The prototype antenna operating in the 2.4 GHz WLAN band showed a significant improvement in isolation between the two CP DRAs.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Malathi Kanagasabai, Padmathilagam Sambandam, M. Gulam Nabi Alsath, Sandeepkumar Palaniswamy, Abinaya Ravichandran, Cibita Girinathan
Summary: This paper reports a compact body-worn circular polarized textile monopole antenna for wearable applications. The antenna is fabricated on a jean fabric, offering flexibility, lightweight, and easy integration into human clothes. With various design techniques, circular polarization is achieved, resulting in good overall performance.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Tian-Wen Chen, Wen-Wen Yang, Yan-Hui Ke, Jian-Xin Chen
Summary: In this letter, a circularly polarized hybrid dielectric resonator antenna (DRA) with wide bandwidth and compact size is proposed. Three CP modes, including cross-slot mode, DR mode, and distributed patch mode, are combined for broadband operation. The cross-slot acts as a radiator and part of the feeding structure, providing the first CP mode and exciting the other two CP modes. The DR and patch within the DR generate two additional CP modes without increasing the size. Through optimization, these three CP modes are combined to achieve a wide operating bandwidth with a compact size of 0.39 x 0.39 x 0.14 ?(3)(0).
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Xiaohe Cheng, Zihao Liu, Yuan Yao, Tao Yu, Junsheng Yu, Xiaodong Chen
Summary: A novel millimeter-wave wideband circularly polarized horn antenna using iris polarizer is reported with improved electrical contact at high frequencies. Analysis of air gap effects on antenna performance was conducted, showing that small air gaps do not harm performance after loading a metasurface. Experimental results confirmed good performance with 37.8% bandwidth from 75 to 110 GHz.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Geochemistry & Geophysics
Maryam Salim, Roger de Roo, Mohammad Mousavi, Kamal Sarabandi, Anthony W. England
Summary: This letter introduces a new hardware setup to suppress radio frequency interference (RFI) in wideband autocorrelation radiometry (WiBAR) microwave radiometer technique. By enhancing the WiBAR instrument with a tunable comb filter, the performance can be improved and the impact of RFI can be reduced.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Geochemistry & Geophysics
Maryam Salim, Shurun Tan, Roger D. De Roo, Andreas Colliander, Kamal Sarabandi
Summary: This article presents a unified framework for vegetation scattering using radiative transfer theory, suitable for both passive and active remote sensing of vegetated land surfaces, especially those with large vegetation water contents (VWC) like forests. The framework allows for modeling microwave signatures of vegetated fields with the same physical parameters describing vegetation structure, and the iterative approach used can include higher order scattering effects, essential for accurate modeling in areas with large VWCs such as forests. Multiple scattering is shown to be crucial for accurate forward modeling, especially over forested areas, and the proposed model is validated with passive and active L-band sensor (PALS) measurements, demonstrating its applicability.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Abdulrahman Aljurbua, Kamal Sarabandi
Summary: This article introduces a method for detecting and localizing oil pipeline leaks using 3-D subsurface multistatic imaging radar. By identifying and eliminating signals from the pipeline, the detectability of leaks is improved. Simulation and measurement results demonstrate the effectiveness of the proposed approach in detecting and localizing pipeline leaks.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Geochemistry & Geophysics
Abdulrahman Aljurbua, Kamal Sarabandi
Summary: A novel 3-D subsurface multistatic imaging radar with a focusing algorithm specifically designed for pipeline detection is demonstrated, showing significantly better imaging performance and the ability to detect and locate metallic as well as dielectric pipes.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Engineering, Electrical & Electronic
Fikadu T. Dagefu, Jihun Choi, Brian M. Sadler, Kamal Sarabandi
IEEE ANTENNAS AND PROPAGATION MAGAZINE
(2023)
Article
Engineering, Electrical & Electronic
Kamal Sarabandi, Menglou Rao
Summary: This article investigates the merits of impedance matching a small antenna to the receiver's impedance. The goal is to prove that connecting a small antenna with low radiation resistance and high input reactance directly to a high-impedance receiver can significantly improve the signal-to-noise ratio (SNR) compared to a standard 50 $\Omega $ input-impedance receiver. Theoretical analysis and experimental results demonstrate that a high-impedance receiver provides a higher SNR even without impedance matching, and a small antenna connected to a high-impedance receiver offers a wide bandwidth and overcomes the gain-bandwidth limitation of small antennas.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Tanner J. Douglas, Kamal Sarabandi
Summary: This communication describes the design of a planar spatial power divider structure, which can split the energy of a wave incident at 45 degrees into a transmitted component and a reflected component. The power divider is polarization-independent, as reflection and transmission coefficients are designed to be approximately equal for both TE and TM waves. The design combines all-dielectric metamaterial techniques with concepts of miniaturized-element frequency selective surfaces, and is verified through circuit modeling and full wave electromagnetic simulations. The fabricated device on a silicon wafer exhibits a maximum difference of 0.9 dB between reflection and transmission for both polarizations within the frequency band of 76 to 84 GHz. Furthermore, the spatial power divider has been integrated into the design of a polarimetric E-Band radar's common-aperture transceiver antenna system.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Geochemistry & Geophysics
Abdulrahman Aljurbua, Kamal Sarabandi
Summary: This article demonstrates a novel 3-D forward scattering model and dynamic grid search-based inversion algorithm for detecting and localizing multiple buried pipelines using multistatic synthetic aperture radar (SAR) configuration. By considering both the phase and amplitude of the scattered field and casting the inversion problem as an optimization problem, the detection and localization resolutions are improved for extended targets. The forward scattering model and inversion algorithm are validated and compared with a basic focusing algorithm using full-wave simulations and experimental data, showing improved range and cross-range detection and localization resolutions.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Engineering, Electrical & Electronic
Behzad Yektakhah, Kamal Sarabandi
Summary: This paper presents a fast and accurate numerical method for modeling wave propagation and scattering in random media. The method divides the random medium into finite slabs, each modeled as a network with multiple input/output ports representing rays with different polarizations and directions. The cascaded networks of slabs can be used to find the response of the random medium to any arbitrary source. The proposed method considers multiple scattering among all scatterers and can model both the mean and fluctuating parts of waves in the random medium. It is demonstrated by calculating specific attenuation in rain media and comparing the results with available data in the literature.
IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Aditya Varma Muppala, Kamal Sarabandi
Summary: This study addresses the problem of detecting concealed weapons using a low-cost 3-D imaging radar system. An alternative method of generating a synthetic array, called affine phase center translations, is proposed. A synthetic 2-D array is generated with a dynamic dual reflector antenna system and a single transceiver. The system is tested in different concealed weapons detection scenarios, achieving high-quality 3-D images that successfully identify the weapons while maintaining individual privacy.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Aditya Varma Muppala, Adam Kaleo Roberts, Kamal Sarabandi
Summary: This article proposes a device based on epsilon-near-zero (ENZ) supercoupling theory for real-time measurement of the complex dielectric constant of liquids at X-band. The device consists of a narrow waveguide channel operating at cut-off frequency and a micro-3-D-printed sample holder to achieve a large field enhancement and prevent energy leakage. The device provides sensitive measurements over a wide range of permittivities and can be fabricated in two variations for higher accuracy or higher sensitivity. A full-wave simulation-based forward model is developed and optimized, and an inversion is performed to find the complex permittivity from measured scattering parameters. Experimental results show good agreement with published literature.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Geochemistry & Geophysics
Abdulrahman Aljurbua, Hussein N. Shaman, Kamal Sarabandi
Summary: Multistatic subsurface synthetic aperture radar (SAR) is a promising tool capable of providing 3-D high-resolution images of targets buried underground. This study presents a simple technique to overcome the dominance of direct and ground reflection signals, enhancing target detection and image quality.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Menglou Rao, Kamal Sarabandi, John Soukar, Nicholas A. Kotov, J. Scott VanEpps
Summary: This study reports the first successful detection of electromagnetic radiation from Staphylococcus aureus biofilms in the gigahertz frequency range and identifies potential communication bands. This finding could contribute to understanding the communication mechanisms among bacterial cells and advancing technologies in biology and communication systems.
IEEE JOURNAL OF ELECTROMAGNETICS RF AND MICROWAVES IN MEDICINE AND BIOLOGY
(2022)
Article
Computer Science, Information Systems
Menglou Rao, Kamal Sarabandi
Summary: This paper presents a very low-profile dual-band dual-polarized millimeter-wave phased array for 5G smartphones. It utilizes two distinct antennas to achieve orthogonal linear polarizations and maintains a low profile. A prototype of a 1 x 4 phased array is successfully designed and implemented, with wide bandwidth and good scanning capability. This work provides a practical solution for implementing low-cost mmWave antennas in smartphones.
Article
Geochemistry & Geophysics
Adib Y. Nashashibi, Mani Kashanianfard, Kamal Sarabandi
Summary: This article introduces a comprehensive technique for calibrating wideband FMCW fully polarimetric radars, addressing polarimetric distortions, nonlinearities, and channel imbalances. The calibration technique estimates and corrects range-dependent nonlinearities in phase, allowing the radar to achieve ideal range resolution. The technique was validated through simulations and measurements on a wideband radar operating over 76.5 – 82 GHz.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
