A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> ELECTRONICS (Total: 207 journals)
The end of the list has been reached or no journals were found for your choice.
   Most Followed Journals

   Top Publishers

   Top Subjects
Similar Journals
Journal Cover
IEEE Antennas and Wireless Propagation Letters
Journal Prestige (SJR): 1.047
Citation Impact (citeScore): 4
Number of Followers: 90  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1536-1225
Published by IEEE Homepage  [228 journals]
  • IEEE Antennas and Wireless Propagation Letters Publication Information

    • Free pre-print version: Loading...

      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • SICL-Fed Balanced Antipodal Dipole Antenna With Wideband Operation and
           Cross-Polarization Improvement at Millimeter-Wave Band

    • Free pre-print version: Loading...

      Authors: Kuikui Fan;Xiaofei Fan;Qingquan Tan;Fang Zhu;Yufeng Yu;Guo Qing Luo;
      Pages: 447 - 451
      Abstract: A substrate integrated coaxial line-fed balanced antipodal dipole antenna array is proposed for millimeter-wave (MMW) applications in this letter. Different from the traditional dual-armed dipole antenna, a balanced antipodal dipole element with three arms is proposed to improve the cross-polarization level by canceling the vertically polarized electric-field components. A cross-polarization level of less than −20 dB is achieved over the entire frequency band. Meanwhile, a gap is etched on each dipole arm to achieve dual-mode operation and broaden the impedance bandwidth of the dipole element, and an impedance bandwidth of more than 65% is obtained. By combining the proposed dipole elements with the unequal feeding network, a 1 × 8 dipole antenna array is designed, fabricated, and measured. The measured results show that the proposed dipole antenna array can achieve a wide −10 dB impedance bandwidth of more than 54% from 24.5 to 43 GHz, a sidelobe level of low than −18 dB in E-plane, and a cross-polarization level of low than −20 dB. With the merits of wide operating bandwidth, low cross-polarization level, low sidelobe level, low profile, and easy integration, the proposed antenna array is valuable to advanced MMW communication systems.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • A Distribution Feature Prediction Method for Chaff Using Polarized
           Scattering Data

    • Free pre-print version: Loading...

      Authors: Jinben Li;Yanchun Zuo;Lixin Guo;Wei Liu;
      Pages: 452 - 456
      Abstract: This letter proposes a method to obtain the distribution features of a chaff cloud by using its polarized scattering data, which provides a new way to filter the jamming of a chaff cloud. First, the electromagnetic polarization algorithm is adopted to acquire the radar cross section (RCS) of a single element with the incident wave revolving on its axis. The direct-accumulating summation method is then employed to obtain the RCS of a chaff cloud. Whereafter, using integer least squares, we can extract the distribution features, i.e., the lengths, orientations, and mixing ratio of chaff elements. Finally, several measurement and simulation cases are carried out based on the actual scenarios. The errors of extracted distribution features are less than 0.06, which indicates that this method can accurately extract the distribution features of a chaff cloud.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • High Selectivity FSS With Three Independently Controllable Transmission
           Poles Using Matrix Synthesis

    • Free pre-print version: Loading...

      Authors: Xian Wang;Yue Wang;Dongfang Zhou;Dalong Lv;Qikun Liu;
      Pages: 457 - 461
      Abstract: In this letter, a high selectivity frequency selective surface (FSS) with three independently controllable transmission poles (TPs) is proposed by using matrix synthesis. The response with three TPs and four transmission zeros is obtained by employing a triplet topology. The matrix synthesis method provides a theoretical analysis for coupling elements regarding to three independently controllable TPs. Also, the synthesized matrix gives a good prediction of flexile responses with allocated center frequency and bandwidth. To be verified, a finite FSS prototype with 15 × 15 unit cells is fabricated and tested. The measured results are mostly consistent with simulated and synthesized ones, manifesting merits of high selectivity, flexible design, and low profile.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Effective Sparse Recovery Framework for Ultrawideband Robust Plane Wave
           Generator

    • Free pre-print version: Loading...

      Authors: Heng Wang;Weimin Wang;Yongle Wu;Bihua Tang;Xiumin Song;Yuanan Liu;Gert Frølund Pedersen;Wei Fan;
      Pages: 462 - 466
      Abstract: This letter proposes a novel ultrawideband plane wave generator (PWG) design methodology suitable for a low-cost small anechoic chamber. Several novel strategies are proposed to handle various crucial concerns in practice to make the proposed methodology reliable and robust. Specifically, the subarray-based amplitude-only excitation method is capable of reducing the required number of control channels without the need for phase shifters, which can significantly simplify the feeding network complexity. One major concern of the PWG application is the nonnegligible multipath reflections in small anechoic chambers. Thus, a novel regression approach, imposing the constraint of maximum energy outside the quiet zone (QZ), is implemented to suppress the reflection level. For the design of the PWG layout, a compressed sensing-based adaptive backtracking orthogonal matching pursuit (ABOMP) algorithm is proposed. In the simulation, a spherical test zone supporting the ultrawideband frequency over 2.4–5 GHz is synthesized with the proposed methodology, and the effectiveness and robustness are comprehensively investigated.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Stretchable Broadband Absorbers Based on the Hauberk Structure

    • Free pre-print version: Loading...

      Authors: Xingyi Wu;Chen Fu;Chunjie Feng;Jiale Gao;Wubo Chu;Xiaobo Zhu;Wenhua Gu;Daying Sun;Yutao Yue;Wen Wu;
      Pages: 467 - 471
      Abstract: One of the major challenges in the design of flexible microwave absorbers is to achieve flexibility, particularly the stretchability of the overall structure while ensuring broadband absorption. In general, the comprehensive properties of flexible dielectric materials are good enough, whereas those of flexible conductive materials are relatively poor. Materials with both good conductivity and stretchability are rarely reported. In this letter, a stretchable absorber was designed with the conductive material made into the hauberk structure, utilizing the relative movement of the rings of the hauberk to realize the stretchability. At the same time, this structure can achieve extra-broad-band absorption at large incident angles. Approximately 80% absorption under vertically incident TE and TM waves was measured in (10–40) GHz, showing good agreement with the simulation results. When the overall structure was stretched uniaxially by 10%, experiment results showed that the absorption decreased slightly but was still broadband, which agreed well with the simulation results. What is more, the structure maintained broadband absorption under 0°, 45°, and 75° incident angles.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Ultrawideband Shared-Aperture Crossed Tapered Slot Antenna for 5G
           Applications

    • Free pre-print version: Loading...

      Authors: Yang Cheng;Yuandan Dong;
      Pages: 472 - 476
      Abstract: A shared aperture scheme based on a tapered slot configuration is proposed in this letter. The main structure of the proposed antenna is an ultrawideband (UWB) crossed tapered slot with ground. In order to improve the practicality, four 1 × 4 dipole arrays containing feeding networks in the millimeter-wave (mm-wave) band are embedded in the four arms of the crossed tapered slot antenna. Four metal reflectors (or flares) are introduced to increase the gain of the dipole array. Owing to the ultrawideband characteristics of the tapered slot antenna, the proposed slot antenna can cover most sub-6 GHz communication frequency bands (such as LTE bands, N77–N79 bands, etc.). The proposed antenna has a compact volume of $0.5 lambda times 0.5 lambda times 0.38 lambda$, where λ is the free-space wavelength at 1.5 GHz. A prototype is designed, fabricated and tested. The measured results show that a −10 dB impedance bandwidth of 107% (1.5–5 GHz) and 15.8% (25–29.3 GHz) is realized in the sub-6 GHz band and mm-wave band, respectively. The isolation between all ports is higher than 30 dB. The gain variation of the antenna in the low-frequency range is 3.8–7.8 dBi. The peak gain of a single dipole array is approximately 14 dBi. The proposed antenna has the characteristics of shared aperture, low cost, and UWB, which is suitable for 5G microbase station applications.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Spherical Modes Driven Directional Modulation With a Compact MIMO Antenna

    • Free pre-print version: Loading...

      Authors: Abel Zandamela;Nicola Marchetti;Max J. Ammann;Adam Narbudowicz;
      Pages: 477 - 481
      Abstract: In this letter, a compact beamsteering multiple-input-multiple-output (MIMO) antenna is proposed for directional modulation applications. A generalization of the beamsteering principle is presented and by exploiting the antenna's unidirectional beamsteering capability within the entire azimuth plane, the system realizes secure steerable transmissions in the direction of the legitimate receiver, with a low bit error rate of $boldsymbol{10^{-5}}$, while a high error rate of $boldsymbol{10^{-1}}$ is seen outside the desired regions. Numerical and experimental verifications are carried out to validate the proposed concept and comparisons with circular arrays are conducted, revealing that the system achieves comparable performance but with up to $boldsymbol{35%}$ and $boldsymbol{71%}$ reduction in antenna diameter and profile, respectively. The method is proposed as a good candidate to enhance the security of small Internet of Things (IoT) devices.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Highly Miniaturized Self-Quadruplexing Antenna Based on
           Substrate-Integrated Rectangular Cavity

    • Free pre-print version: Loading...

      Authors: Rusan Kumar Barik;Slawomir Koziel;
      Pages: 482 - 486
      Abstract: This letter introduces a novel self-quadruplexing antenna (SQA) architecture using a substrate-integrated rectangular cavity (SIRC) for compact size, wide-frequency redesignability, and high isolation responses. The proposed SQA is developed by engraving two U-shaped slots (USSs) on the top conductor of the SIRC. The USSs are excited by employing four microstrip feedlines to achieve SQA characteristics. The operating frequencies can be tuned independently according to the assumed targets, with a wide tuning range from 2.3 to 7 GHz. The dimensions of USSs are meticulously chosen to achieve high isolation and compact size. An equivalent circuit is suggested to validate the proposed SQA. Finally, the SQA operating at 2.33, 2.96, 5.43, and 6.15 GHz is fabricated and validated. As compared to the earlier SQAs, the proposed antenna offers competitive performance with a compact size of 0.124λ2 (45.6% smaller than the most compact SQA reported in the literature), high isolation of 32.5 dB, and a wide tunable range from 2.3 to 7 GHz. Its measured gain is 4.31, 3.39, 6.12, and 4.34dBi at 2.33, 2.96, 5.43, and 6.15 GHz, respectively.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • High-Gain Omnidirectional Circularly Polarized Array Based on Folded
           Counter-Wound Helix

    • Free pre-print version: Loading...

      Authors: Zhenxin Hu;Zhenge Zhang;Maomi Feng;Wenwei Wang;Ali Al-Sheikh;Wen Wu;Jianqi Liu;
      Pages: 487 - 491
      Abstract: A high-gain omnidirectional circularly polarized (OCP) helical array is reported in this letter. It consists of four identical OCP folded counter-wound helices that are parallel-fed by an equal-split power divider structure. The counter-wound helix's folding technique features a high radiation resistance of 102.1 Ω and a compact size of 0.055 × 0.055 × 0.39 λ03, thus achieving good matching and alleviating the mutual coupling of the shunt-fed array. A prototype is fabricated and tested. Measured results indicate that the array achieves an impedance bandwidth (|S11|
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • An Integral Equation-Based Overlapping Domain Decomposition Method
           Enhanced With Anderson Acceleration

    • Free pre-print version: Loading...

      Authors: Guang-Yu Zhu;Wei-Dong Li;Wei Hong;
      Pages: 492 - 496
      Abstract: In this letter, an integral equation-based overlapping domain decomposition method enhanced with Anderson acceleration (IE-ODDM-AA) is proposed for the solution of the electrically large electromagnetic problems whose memory consumptions are too large for the user's computer to accommodate. By augmenting the traditional Gauss–Seidel-like iterative scheme of the IE-ODDM with a popular fixed point acceleration technique named Anderson acceleration, the convergence behavior of the IE-ODDM is greatly improved. Particularly, for the domain partitioning cases where the traditional scheme of the IE-ODDM diverges, the presented IE-ODDM-AA can still yield convergent solutions. Several numerical examples are provided to validate the proposed method.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Broadband Magnetoelectric Dipole Filtering Antenna for 5G Application

    • Free pre-print version: Loading...

      Authors: Rongxu Hou;Jian Ren;Yan-Ting Liu;Yuan-Ming Cai;Jianxiao Wang;Yingzeng Yin;
      Pages: 497 - 501
      Abstract: A magnetoelectric (ME) dipole filtering antenna with high out-of-band suppression level and high selectivity is proposed in this letter. The intrinsic radiation null of the traditional ME dipole antenna is used, which produces a good filtering response at the edge of the lower passsband. A pair of vertical parasitic metal planes are introduced between the shorted walls and fed through slot coupling, which can be equivalent to an additional magnetic dipole. The radiated electric field of the magnetic dipole is opposite to that of the original antenna at higher frequency, forming a wide stopband radiation null, which greatly improves the high-frequency stopband suppression level of the antenna. Furthermore, a pair of T-shaped coupling stubs are inserted between the shorted wall and electric dipole, producing another radiation null with high roll-off rate at higher frequency. The measurement results show that the −10 dB impedance bandwidth of the proposed antenna is 49.4% (3.2–5.3 GHz). Its low-frequency stopband suppression level is greater than 16.6 dB and high-frequency stopband suppression level is greater than 26.0 dB. Moreover, the antenna radiation pattern is stable and symmetrical in the whole operating passband, and the filtering response is desirable.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Grating Lobe Suppression and Angle Estimation Based on Virtual Antennas
           Filling in Sparse Array

    • Free pre-print version: Loading...

      Authors: Jiangyou Zhu;Peng Lei;Jun Wang;Yaotian Zhang;Changshun Yuan;
      Pages: 502 - 506
      Abstract: When the radar antenna spacing is larger than half wavelength, grating lobes appear in its antenna beam pattern. They could cause the ambiguity in the angle estimation of radar targets due to the similarity of amplitudes between grating lobes and the main lobe. To address such issue, this letter proposes a grating lobe suppression and angle estimation approach for sparse arrays by use of virtual antennas filling. It takes advantage of the distribution characteristics of grating lobes, and first obtains rough estimates of target angles. The least squares method is then employed to generate signals received by virtual antenna elements. Accordingly, the gaps between antenna elements of sparse array could be filled with those virtual ones to form an equivalent uniform full array. Hence, it achieves the grating lobe suppression as well as accurate estimation of target angles. Both simulations and experiments are carried out to verify its effectiveness in different types of sparse arrays.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Rotationally Reconfigurable Single-Element Prism for Enhancing Scanning
           Flexibility of Risley Prism Antenna System

    • Free pre-print version: Loading...

      Authors: Wenyi Shao;Qiang Chen;
      Pages: 507 - 511
      Abstract: In this letter, we propose a rotationally reconfigurable single-element prism that is compatible with the typical Risley prism antenna system. It consists of a pair of rotating decentered phase plates operating at 30 GHz. The equivalent prism angle can be continuously changed between 0° and 14° by simply rotating these two phase plates. An all-dielectric low-cost prototype has been designed, fabricated, and measured, which demonstrates the peak realized gain of 21 dBi can be achieved with a gain variation less than 0.9 dB within the reconfigurable angle range of 0°–14°. Besides, the combination of phase distribution of two rotating phase plates can be used as a new mechanism avoiding using first-order paraxial approximation to realize two-dimensional beam scanning.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • A Wideband Multibeam Pillbox Antenna Based on Differentially Fed
           Leaky-Wave Array

    • Free pre-print version: Loading...

      Authors: Yuanxi Cao;Sen Yan;Wendong Liu;Jianxing Li;
      Pages: 512 - 516
      Abstract: In this letter, a compact wideband multibeam pillbox antenna is proposed based on differential feeding technology. The proposed design focus on extending the operating frequency bandwidth of the leaky-wave antenna (LWA) array with a fixed broadside beam, since the bandwidths of the existing pillbox antennas are always limited by the radiators, especially considering the standard printed circuit board technology with limited layers. To overcome this limitation, a differentially fed LWA is used as the radiator. The two subarrays of the LWAs are excited with oppositely propagating waves through a coupled slot, generating two oppositely directed beams whose combination can produce a fixed broadside beam over a wide operating bandwidth. A 14-element LWA array is fabricated with a pillbox beamforming network (BFN) to verify its design theory. The simple feeding structure of the LWA makes the LWA array can be stacked on the top of the pillbox BFN, achieving antenna miniaturization. The measured results show that the proposed antenna can achieve the −10 dB impedance matched bandwidth from 14.0 to 16.0 GHz and seven beams with ±34° beam scanning range. The broadside beam has a gain variation range of 16.8–20.2 dB over the operating band.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Reduced Cross-Polarization and Backside Radiations for Rectangular
           Microstrip Antennas Using Defected Ground Structure Combined With
           Decoupling Structure

    • Free pre-print version: Loading...

      Authors: Bingyi Qian;Xiaoming Chen;Luyu Zhao;Juan Chen;Ahmed A. Kishk;
      Pages: 517 - 521
      Abstract: For cross-polarization (XP) reduction of microstrip antenna, it is proposed to use asymmetric defected ground structure (DGS) under the patch, which perturbs the TM02 mode. Unlike conventional DGS, the proposed DGS reduces the XP without increasing the back radiation. A method of higher order modes and surrounding electric fields is used to explain the DGS. The feasibility and superiority of the proposed scheme are further verified by constructing H-plane linear 4-element arrays. The XP reduction and decoupling are achieved simultaneously, as supported by simulation and measurement.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Active Metasurface-Based Reconfigurable Polarization Converter With
           Multiple and Simultaneous Functionalities

    • Free pre-print version: Loading...

      Authors: Samiran Pramanik;Saikat Chandra Bakshi;Chaitali Koley;Debasis Mitra;Alessio Monti;Filiberto Bilotti;
      Pages: 522 - 526
      Abstract: We introduce a new concept of three-states polarization converting metasurface (TS-PCM) based on p-i-n diodes. The proposed structure can offer three distinct wave manipulation functionalities: linear polarization to orthogonal linear polarization (LP-OLP), linear polarization to circular polarization (LP-CP), and linear polarization to full reflection (LP-FR) state. Unlike previous structures, the multiple conversion features are simultaneously achieved in different frequency ranges, depending on the operating state of diode (off or on). Finally, a sample prototype was fabricated and the experimental results were verified with the simulated ones.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Designing a Compact Helical Slot Antenna for Multiple Circularly Polarized
           OAM Modes

    • Free pre-print version: Loading...

      Authors: Ehsan Koohkan;Saughar Jarchi;Ayaz Ghorbani;Mohammad Bod;
      Pages: 527 - 530
      Abstract: In this letter, a helical slot antenna for generating multiple orbital angular momentum (OAM) modes is proposed. The proposed antenna consists of four concentric helical slot array antennas, which are excited by an annular microstrip line. The number of each helical slot, and length of microstrip feed are chosen to create circularly polarized OAM modes of 0, −1, −2, and −3 at 3.5 GHz frequency with more than 10% fractional bandwidth. The final multimode antenna has 89 mm in diameter and 19.1 mm in height. A prototype of the proposed compact antenna is fabricated. From the simulation and measurement results, prominent spiral phase planes are observed at all antenna ports. Both the measurement and simulation results show that the proposed compact antenna has valuable features to produce different vortex modes.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Dual-Band Reconfigurable Flexible Antenna With Independent Frequency
           Tunability

    • Free pre-print version: Loading...

      Authors: Quoc Hung Dang;Shengjian Jammy Chen;Damith Chinthana Ranasinghe;Christophe Fumeaux;
      Pages: 531 - 535
      Abstract: A dual-band frequency-reconfigurable flexible textile and foam antenna with independent tunability is presented in this letter. The proposed antenna operates simultaneously in a $text{TM}_{0(0.5)0}^{z}$ mode and a higher order mode with individual frequency tunability centered at the 2.45 and 5.8 GHz industrial, scientific, and medical bands. The relative frequency tuning range at the lower band is 41.1%, while that at the higher band is 29.9%. The antenna is fabricated and measured to validate the concept. The antenna prototype operates as expected and maintains robust performance in various bending configurations through its individual dual-band frequency reconfigurability, which suggests its practicality for wearable applications.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Quantum Radiating Arrays and Their Directivity: A Dynamical Open System
           Approach

    • Free pre-print version: Loading...

      Authors: Said Mikki;
      Pages: 536 - 540
      Abstract: We investigate the directive properties of radiating quantum antennas comprised of coupled two-level (qubit) systems interacting with bosonic modes and excited by classical fields. A directivity formula inspired by classical antenna theory is proposed. The density operator of a coupled two-level quantum dot (qubit) array, excited by classical external signals with variable amplitude and phase, is evolved in time using the Gorini–Kossakowski–Sudarshan–Lindblad master equation. We illustrate the method in a numerical example where it is shown that manipulating the phase excitations of individual quantum dots may significantly enhance the directive radiation properties of the quantum dot antenna system.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Miniaturization of Rotman Lens Using Array Port Extension

    • Free pre-print version: Loading...

      Authors: Qiuyan Liang;Baohua Sun;Gaonan Zhou;
      Pages: 541 - 545
      Abstract: This letter proposes a miniaturization design of Rotman lens using array port extension technique. The array ports of the proposed 4 × 12 Rotman lens are extended from an initial 4 × 7 Rotman lens through a port extension (PE) network to achieve a smaller equivalent lens body. The initial Rotman lens and the topology for the PE network are designed based on the analysis of phase distributions along the extended array ports when different beam ports are excited. The proposed design allows all the beam pointing angles to be consistent before and after extension at center frequency. A prototype working at X-band was fabricated. The measured results show that all beam ports are matched well, and high isolations between beam ports are achieved from 8 to 12 GHz. The Rotman lens provides a ±29° scanning range with four uniformly distributed beams at 10 GHz. The beam pointing angles remain relatively stable within 20% frequency bandwidth, with the maximum angle distortion of ±3°.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Estimation of Absorbed Power Density Based on Spherical Wave Expansion to
           Plane Wave Expansion for Exposure Assessment at 30 GHz

    • Free pre-print version: Loading...

      Authors: Zixuan Feng;Jianhua Wang;Yinliang Diao;
      Pages: 546 - 550
      Abstract: The international guidelines and standard specified the area-averaged absorbed/epithelial power density (APD/EPD) as the basic restriction at frequencies above 6 GHz. Assessment methods for APD are current under the consideration of standardization organizations. In this study, we first showed the enhancement of the APD due to the antenna/body interaction using full-wave simulations. We then proposed a hybrid method combining the spherical near-field measurement and numerical simulation of the exposure dose in human body, using an equivalent source reconstructed on the total field/scattered field boundary using the spherical wave expansion to plane wave expansion. By comparing with the full-wave simulated APD at 30 GHz for various antenna arrays, the proposed method gives a rather accurate estimation of the upper bound of the area-averaged APD (with relative differences < 28%). It can be utilized as an efficient method for electromagnetic safety assessment as the need for specific measurement equipment is eliminated.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • A Single-Layer Filtering Antenna With Two Controllable Radiation Nulls
           Based on the Multimodes of Patch and SIW Resonators

    • Free pre-print version: Loading...

      Authors: Donghao Li;Changjiang Deng;
      Pages: 551 - 555
      Abstract: A single-layer filtering hybrid antenna with low profile and high selectivity is presented. The proposed antenna is composed of a triangular patch and a substrate integrated waveguide (SIW) cavity with triangular slot and U-shaped slot etched on the top surface. The patch is embedded in the triangular slot. Four modes can be generated by the hybrid structure. That is, the TM10 mode of the patch, the right half-TE11, the modified right half-TE11 and the TE1.5, 1 modes of the SIW cavity are selected. By merging the four modes into a single passband, the impedance bandwidth is broadened, and the frequency selectivity is enhanced. There are two radiation nulls at the lower and upper edges of the passband, which can be controlled independently. In addition, part of the shorting pins surrounding the SIW cavity is truncated to decrease the operating frequency and increase the out-of-band rejection. The measured –10 dB impedance bandwidth ranges from 3.44 to 3.62 GHz with sharp frequency selectivity and more than 18 dB out-of-band suppression level.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Pin-on-Substrate Gap Waveguide: An Extremely Low-Cost Realization of
           High-Performance Gap Waveguide Components

    • Free pre-print version: Loading...

      Authors: Ali K. Horestani;Michal Mrozowski;
      Pages: 556 - 560
      Abstract: Considering the limitations of currently available technologies for the realization of microwave components and antennas, a trade off between different factors including the efficiency and fabrication cost is required. The main objective of this letter is to propose a novel method for the realization of gap waveguides (GWGs) that take advantage of conventional printed circuit board fabrication technology, thus are low cost and light weight. Moreover, by avoiding dielectric loss and minimizing conductive loss, the proposed GWGs benefit from a very low loss. To highlight potential applications, a high-performance slot-array antenna based on the proposed GWG is presented.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Measurements and Modeling of Large-Scale Channel Characteristics in Subway
           Tunnels at 1.8 and 5.8 GHz

    • Free pre-print version: Loading...

      Authors: Xuejian Zhang;Ruisi He;Mi Yang;Bo Ai;Shaopeng Wang;Weiming Li;Wenpu Sun;Lizhe Li;Peng Huang;Yunlei Xue;
      Pages: 561 - 565
      Abstract: Radio propagation characteristics in subway tunnels are significant for designing reliable wireless communications. To obtain large-scale channel characteristics, extensive propagation measurements are conducted in a straight subway tunnel at 1.8 and 5.8 GHz, respectively. Based on the measurements, some typical large-scale channel parameters are extracted and modeled, such as path loss, shadow fading, and channel correlation. The path loss exponents are found to be 2.83 and 2.55 at 1.8 and 5.8 GHz, respectively, with shadow fading standard deviation of 1.58 and 2.58 dB. Shadow fading decorrelation distance is 8.71 m for 1.8 GHz and 11.65 m for 5.8 GHz, respectively. Moreover, cross-correlation coefficient of shadow fading in two dual-link scenarios is around 0.1, which shows that there is fairly low cross-correlation in a subway tunnel. The results in this letter are useful for link budget, handover scheme design, and network planning of subway communication system.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • On the Use of Metal-Only Polarization Rotation Elements for Reflectarray
           Designs

    • Free pre-print version: Loading...

      Authors: Yifeng Chen;Lu Guo;Wenjie Feng;Xiaodong Chen;
      Pages: 566 - 570
      Abstract: A reflectarray antenna employing metal-only polarization rotation elements is proposed in this letter. The element is composed of double metallic layers separated by an air gap and rotates the reflection wave polarization orthogonally with respect to that of the incidence wave. By tuning the structural dimension, a pair of elements with 90° phase difference are obtained. These two elements together with their mirroring images can be employed as a 2-bit phase shifter with 0°, 90°, 180°, and 270° phase shift from 9 to 10.8 GHz. For proof-of-concept, a metal-only reflectarray containing 225 unit-cells is developed and tested. According to experimental results, the 1 dB and 3 dB gain bandwidth of the metal-only reflectarray are 19% and 38% respectively while the peak aperture efficiency is 34%. These encouraging features demonstrate that reflectarrays can be successfully designed with metal-only polarization rotation elements and present a good potential for space applications.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • A Compact Metasurface Antenna Array With Diverse Polarizations

    • Free pre-print version: Loading...

      Authors: Chen Zhao;Shijiong Zhang;Feng Wang;Wen Geyi;
      Pages: 571 - 575
      Abstract: In this letter, a compact metasurface antenna array with diverse polarizations is proposed. The array element is a dual-polarized metasurface antenna driven with a square patch. In order to have compact size and low sidelobes for the antenna array, shared radiating elements are applied for both polarizations with a size reduction of 18.8% for a 1 × 4 antenna array. The diverse polarization property is achieved with the method of maximum power transmission efficiency (MMPTE), in which a dual-feed patch antenna connected to an ideal power combiner is chosen as the receiving antenna. With different scattering matrices of the power combiner, it is easy to calculate the excitation distribution for any polarizations with maximum gain. For demonstration, the antenna array with diverse polarizations is designed, fabricated, and measured.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Dual-Polarized Probe for Planar Near-Field Measurement

    • Free pre-print version: Loading...

      Authors: Sabin Kumar Karki;Juha Ala-Laurinaho;Ville Viikari;
      Pages: 576 - 580
      Abstract: A dual-polarized probe enables the simultaneous sampling of two orthogonal polarizations, which decreases the time for the characterization of co- and cross-polar properties of the antenna under test in transmission mode by 50%. In this work, a dual-polarized probe comprising of a square waveguide and grating polarizer-based orthomode transducer is presented. The Ku-band dual-polarized probe is manufactured in-house using additive manufacturing and coated with conductive paint. The simulated and measured $-$10 dB impedance bandwidth is between 10.7 and 14.5 GHz. The peak simulated and measured coupling between the orthogonal polarizations is less than $-$60 dB and $-$40 dB, respectively.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Measurement Trials and Modeling of Radio Propagation Through Small-Scale
           Fire Using Pinus pinaster Fuel Bed

    • Free pre-print version: Loading...

      Authors: Stefânia Faria;Mário Vala;Pedro Coimbra;Nuno Leonor;João M. Felício;Carlos A. Fernandes;Carlos Salema;Rafael F. S. Caldeirinha;
      Pages: 581 - 585
      Abstract: This letter presents measurement results and initial physical modeling of the radiowave propagation phenomena in the presence of fire using Pinus pinaster fuel heaps. To this extent, this letter reports on small-scale measurement trials carried out at 700 MHz on Pinus pinaster fuel bed on fire and subsequent validation of simulation results of the propagation phenomena behavior based on the intertwined use of both the fire dynamics simulator and the cold plasma model. Excess attenuation of up to 1.52 dB was observed in measured results, which is thought to be critical considering it is a small-scale fire scenario composed of a 1 × 1 m$^{2}$ with 0.6 kg of pine needles
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • CMA Approach for a DGS-Based Wideband Circular Patch Antenna With Low
           Cross Polarization

    • Free pre-print version: Loading...

      Authors: Deepak Kumar Naik;Rajanikanta Swain;Dhruba Charan Panda;Rabindra Kishore Mishra;
      Pages: 586 - 590
      Abstract: This letter presents a design approach for a defected ground structure (DGS)-based wideband circular microstrip patch antenna using the characteristic mode analysis (CMA). It emphasizes improving two design aspects: 1) cross polarization reduction and 2) bandwidth enhancement. The CMA unveils the intrinsic characteristic modes in the patch and ground plane, and then, undesired modes are suppressed using a DGS, reducing cross-polarized radiations. Another defect, strategically incorporated into the same DGS, enhances a higher-order nonradiating mode to radiate and increases bandwidth. The proposed design fabricated on an FR-4 substrate achieves a $simeq$ 16% impedance bandwidth (5.7–6.7 GHz) with dimensions $boldsymbol{0.8lambda _{0}times 0.8lambda _{0}times 0.03lambda _{0}}$ ($boldsymbol{lambda}_{boldsymbol{0}}$ being the free-space wavelength at 6 GHz) and 10–15 dB average cross polarization reduction at $pm$60° angle of boresight. The measured results from a fabricated prototype agree well with the proposed design.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • A Circularly Polarized Hybrid Dielectric Resonator Antenna With Wide
           Bandwidth and Compact Size

    • Free pre-print version: Loading...

      Authors: Tian-Wen Chen;Wen-Wen Yang;Yan-Hui Ke;Jian-Xin Chen;
      Pages: 591 - 595
      Abstract: A circularly polarized (CP) hybrid dielectric resonator antenna (DRA) with wide bandwidth and compact size is proposed in this letter. Three CP modes can be combined together for broadband operation, which are the cross-slot mode, the DR mode, and the distributed patch mode, respectively. The cross-slot functions as both a radiator and part of the feeding structure, providing the first CP mode and excites the other two CP modes, respectively. The 2 × 2 distributed patch is inserted inside the DR. The DR and the patch can generate another two CP modes without enlarging the DR size. Through optimization, these three CP modes can be combined to achieve a wide operating bandwidth with a compact size of 0.39 × 0.39 × 0.14 λ03 (λ0 is the free-space wavelength at the center frequency of 3.5 GHz). A prototype was fabricated and measured for demonstration. It has an impedance bandwidth of 38.9% (2.9–4.3 GHz), an axial ratio bandwidth of 34.3% (2.9–4.1 GHz), and a realized gain between 5.6 and 6.7 dBi.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • $V$ -Band+Frequencies&rft.title=IEEE+Antennas+and+Wireless+Propagation+Letters&rft.issn=1536-1225&rft.date=2023&rft.volume=22&rft.spage=596&rft.epage=600&rft.aulast=Joseph;&rft.aufirst=Brecht&rft.au=Brecht+De+Beelde;David+Plets;Wout+Joseph;">Characterization of Vegetation Loss and Impact on Network Performance at
           $V$ -Band Frequencies

    • Free pre-print version: Loading...

      Authors: Brecht De Beelde;David Plets;Wout Joseph;
      Pages: 596 - 600
      Abstract: Wireless communication systems using millimeter-wave (mmWave) frequencies can be used for high-throughput applications such as fixed wireless access, where static line-of-sight links are used to provide internet connectivity. The directive antennas are typically mounted on building facades above street level. Therefore, the wireless links are mainly subject to attenuation due to atmospheric absorption, rain, and vegetation. In this letter, we present vegetation loss measurements at $V$-band frequencies ranging from 50 to 75 GHz, using a spectrum analyzer-based channel sounder. Existing vegetation models, including the vegetation-dependent exponential decay (VED) model, are validated based on the measured vegetation loss. Furthermore, IEEE 802.11ad transceivers are used for the validation of the vegetation models, and to evaluate the influence of vegetation on the network performance via packet error rate (PER) and throughput measurements.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Estimating Annual Temperate Rain Attenuation Distributions at 20/40 GHz
           With a High-Resolution Numerical Weather Prediction Model

    • Free pre-print version: Loading...

      Authors: Laurent Quibus;Valentin Le Mire;Julien Queyrel;Xavier Boulanger;Laurent Castanet;Laurent Féral;
      Pages: 601 - 605
      Abstract: Earth-space communications are to make use of higher frequencies, at and above 20 GHz, to offer new services and increased data rates. A consequence is a strong attenuation of the carrier waves by the troposphere, particularly during rain events. The statistical characterization of the rain attenuation on high-frequency channels is thus paramount to their link budget. Traditionally this knowledge is obtained via long-term ground measurements of spaceborne beacon signals. Here, simulated results based on numerical weather prediction models are considered as an alternative. A comparison is given based on two years of beacon data at 20 and 40 GHz in Toulouse (France). Four parametrizations of the weather research forecasting model's microphysics are tested: the best performances are achieved with the NSSL-2 moment scheme.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Fully Planar Single/Fixed-Beam Ultrawideband Leaky-Wave Antenna Based on
           Leaky Grounded Coplanar Waveguide

    • Free pre-print version: Loading...

      Authors: Yongsheng Pan;Tianqi Ao;Yuandan Dong;
      Pages: 606 - 610
      Abstract: A fully planar single- and fixed-beam leaky-wave antenna (LWA) is proposed based on the leaky grounded coplanar waveguide (GCPW). This antenna consists of a leaky GCPW, a parallel plate waveguide (PPW) prism, and a metal-strip transition. It generates a fixed-beam leaky wave radiation from the GCPW to the PPW, and then radiates it into the free-space through the metal-strip transition. Because the GCPW is nearly nondispersive, this antenna exhibits a fixed-beam radiation inherently, making it much simpler to design and fabricate compared to other fixed-beam LWAs. Measured results show the proposed antenna achieves a peak gain of 19.4 dBi, 3 dB gain bandwidth of 28.8 GHz to> 40 GHz (> 32.6%), −10 dB impedance bandwidth of larger than 26–40 GHz (> 42.4%), and a small beam shifting range of only 3° (±1.5°) within 26–40 GHz, which make it suitable for applications such as point-to-point communication.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Reconfigurable Folded Transmitarray Antenna With Low-Profile Based on
           Metasurfaces

    • Free pre-print version: Loading...

      Authors: Tang-Jing Li;Guang-Ming Wang;Wen-Long Guo;Ke-Wei Xin;Jia-Qi Han;Hai-Peng Li;
      Pages: 611 - 615
      Abstract: A reconfigurable folded transmitarray antenna (RFTA) with fully planar structure is presented in this letter. It consists of an electronically reconfigurable metasurface and a polarization rotating metasurface (PRMS). A pair of PIN diode switches is integrated on the reconfigurable meta-atom to realize the 1-bit transmission phase manipulating, and a patch antenna is integrated on the center of the PRMS to feed the RFTA. Through twice reflecting, polarization rotating, and transmission phase compensation, the spherical wave from the feed is transformed into the scannable pencil-shaped beam. Meanwhile, the antenna profile is reduced to about 1/3 compared to the traditional reconfigurable transmitarray antenna (RTA). The RFTA prototype with 12 × 12 elements is designed, fabricated, and measured. Experimental results show that the gain of 13.4 dBi at 5.8 GHz is obtained and the two-dimensional beam scanning angle covers ±60°. This work significantly reduces the profile of traditional RTA, making it a promising candidate for the wireless communication system with limited space.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Pattern-Reconfigurable Antenna Using Low-Profile Electric and Magnetic
           Radiators

    • Free pre-print version: Loading...

      Authors: Shengnan Zhao;Zhan Wang;Yuandan Dong;
      Pages: 616 - 620
      Abstract: A compact antenna based on low-profile radiator pairs with high pattern reconfiguration diversity is proposed in this letter. The antenna consists of four hybrid radiator pairs and a reconfigurable feeding network. By switching the on/off states of four positive-intrinsic-negative (PIN) diodes, which are integrated into the reconfigurable network, the activation states of the four radiator pairs can be separately controlled. Each pair employs one low-profile electric radiator (monopole) and one low-profile magnetic radiator for stable directional radiation and structural compactness. As a result, the radiation beam can be electrically and directionally scanned in the horizontal plane (ϕ-plane). Eight different radiation modes can be obtained within an overlapped bandwidth. A prototype is designed, fabricated, and tested. Good impedance matching and stable directional radiation patterns are achieved over the entire operating band from 3.4 to 3.70 GHz in the measurement. The fabricated antenna features a compact size of 0.46 λg × 0.46 λg × 0.13 λg (λg represents the guided wavelength at 3.5 GHz). The proposed antenna is well-suitable for space-limited Sub-6 GHz smart and intelligent applications.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Gain Improvement of Vivaldi MIMO Antenna With Pattern Diversity Using
           Bi-Axial Anisotropic Metasurface for Millimeter-Wave Band Application

    • Free pre-print version: Loading...

      Authors: Manish Singh;Manoj Singh Parihar;
      Pages: 621 - 625
      Abstract: In this letter, a high gain Vivaldi multi-input–multi-output (MIMO) antenna with orthogonal pattern diversity for millimeter-wave (mm-Wave) band application is proposed with the reduction paradigm towards nonuniform phase errors (at Vivaldi aperture) through metasurface loading. The nonuniform phase error limits the endfire gain (4.9–5.9 dBi) and hence the efficacy of the system. To compensate the phase error and improve the gain, a bi-axial anisotropic metasurface unit cells have been thoroughly investigated in systematic manner and strategically loaded at Vivaldi MIMO antenna. The endfire gain improvement with metasurface loading is reflected to be $sim$73% higher at 28 GHz with gain variation 8.2–10.2 dBi in the band of interest. Simultaneously, high pattern integrity behavior of the MIMO system is confirmed by the appreciable 1 dB gain bandwidth (33%). The standard port-to-port isolation (>15 dB) and MIMO performance parameters (ECC < 0.2 and TARC> 10 dB) confirms its suitability for mm-Wave band application.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Scattering Analysis of Finite Periodic Array in the Vicinity of Arbitrary
           Object Using Hybrid Macro Basis Function Method

    • Free pre-print version: Loading...

      Authors: Tao Guo;Ping Du;
      Pages: 626 - 630
      Abstract: A hybrid macro basis function (MBF) method is proposed to analyze the finite periodic array in the vicinity of an arbitrary object. The array cells and object are modeled using the low order basis functions firstly. Afterwards, the MBFs defined on the cells are constructed using the modified accurate subentire domain basis function method. The MBFs on the object can be obtained using the characteristic basis function method. The total number of MBFs defined on the array cells and object is far less than that of the low order bases. Another advantage of the proposed method is that multiple excitations can be efficiently computed. Simulation results show that good agreement between the proposed method and other techniques is reached. In addition, computational efficiency is validated.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Pattern Synthesis for Different Sparse Planar Arrays by a Hybrid
           Unconstrained-Heuristic Approach

    • Free pre-print version: Loading...

      Authors: Xin-Kuan Wang;Gui-Bao Wang;Lei Wang;
      Pages: 631 - 635
      Abstract: A hybrid approach that combines the strategy of partial density tapering (PDT) and the multiobjective particle swarm optimization (MOPSO), called PDT-MOPSO, is proposed to address the synthesis of sparse planar arrays (SPAs) of different shapes. By performing the PDT, not only the strong constraint of element placement in SPAs is eased to nonconstrained issue, but also the element locations are forced to follow the distribution of density tapering somewhat to facilitate the sidelobe suppression. Then, by taking the sidelobe level (SLL) and directivity as the optimization objectives, the traditional MOPSO is used to optimize the element locations so that the SPAs with reduced number of elements, minimized SLL and nondegraded directivity are achieved. Some numerical instances confirmed the effectiveness of the proposed method.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Estimate of Throughput Improvement Due to a Metasurface Reflector in 5G
           Millimeter-Wave Links

    • Free pre-print version: Loading...

      Authors: Andrey Kobyakov;Aramais R. Zakharian;
      Pages: 636 - 640
      Abstract: Rigorous solution of Maxwell's equations is used to show that electromagnetic field scattered by a metasurface (MS) reflector based on engineered phase gradient closely resembles the scattering pattern of a properly irradiated metal reflector of the same size. Approximate analytical expressions for the spatial distribution of the scattered signal are derived to estimate an increase in the achievable bit rate in a 5G-NR link due to an MS reflector. A figure-of-merit (FoM) based on the wireless link throughput is introduced. The FoM analysis shows that to affect a 5G wireless link, the MS reflector should exceed some critical size, which depends on the propagation distances. Furthermore, performance of a larger reflector initially increases linearly with its size, followed by a slower sublinear growth.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Design of High-Gain Single-Layer Endfire Antenna Using Phase-Reversed
           Asymmetric Spoof Surface Plasmon Polaritons

    • Free pre-print version: Loading...

      Authors: Mingru Xiao;Amir K. Rashid;Baiyang Liu;Rengui Fan;Qingfeng Zhang;
      Pages: 641 - 644
      Abstract: We present a novel endfire antenna based on asymmetric spoof surface plasmon polaritons (SSPPs) and phase-reversal technique. SSPPs structure allows it to be fabricated on a single-layer printed circuit board. Asymmetric SSPPs elements were employed to fulfill the condition of endfire radiation, and meanwhile, phase-reversal technique provides a high gain for the antenna. To verify the proposed design principle, a prototype was fabricated and measured. It exhibits a peak gain of 16.2 dBi within the operational frequency band of 17–19 GHz, featuring the highest endfire gain among all single-layer designs.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Aperture Reduction Using Downward and Upward Bending Arms for
           Dual-Polarized Quadruple-Folded-Dipole Antennas

    • Free pre-print version: Loading...

      Authors: Hui Yang;Ge Zhao;Jiayue Jiang;Ting Liu;Luyu Zhao;Yingsong Li;Yuanming Cai;Jin Yao;
      Pages: 645 - 649
      Abstract: A method to miniaturize the aperture of a dual-polarized quadruple-folded-dipole (QFD) antenna by bending its arms downward or upward is proposed in this letter. Two practical prototypes called downward-bending-arm (DBA) antenna and upward-bending-arm (UBA) antenna are presented and elaborated. Both the DBA and UBA antennas have four pairs of arms bent downward or upward along the four edges of the planar QFDs, respectively, which enable the aperture of the DBA and UBA antennas to shrink to around $0.24{lambda }_0 times 0.24{lambda }_0$ (${{rm{lambda }}}_{0}$ is the free-space wavelength at 2 GHz). Both antennas can achieve relatively small apertures while ensuring good matching, isolation, and radiation performances within the band of interest. Especially, the DBA antenna has a lower profile than the UBA antenna while the UBA antenna outperforms the DBA antenna in realized gain by approximately 1 dB. Meanwhile, the UBA antenna has narrower half-power beam width, which will be beneficial in compact massive multiple-input–multiple-output antenna arrays for improved radiation patterns.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Feedline Design for a Series-Fed Binomial Microstrip Antenna Array With No
           Sidelobes

    • Free pre-print version: Loading...

      Authors: Nagalakshmaiah Kalva;Busineni Mahesh Kumar;
      Pages: 650 - 654
      Abstract: In this letter, a novel feedline configuration is proposed to eliminate the sidelobes by controlling the current distribution. This is achieved by adjusting the widths of the feedline of a series-fed microstrip antenna array. Even–odd mode analysis is provided to understand the effect of the feedline widths on current distribution. A binomial series-fed five-element microstrip antenna array is designed with the proposed feedline. The designed microstrip series-fed binomial array has no sidelobes in the radiation pattern with a realized gain of 11.1 dBi at the resonance frequency with 80% efficiency. It has a cross-polar level of $-$40 dB and a front-to-back ratio of 20 dB. A prototype of the proposed design has been realized. The simulated and measured results are in good agreement.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Effects of a Cylindrical Metallic Cavity on the Radiation of
           Longitudinally Polarized Limited-Diffractive Bessel Beams

    • Free pre-print version: Loading...

      Authors: Santi C. Pavone;Loreto Di Donato;Gino Sorbello;
      Pages: 655 - 659
      Abstract: This letter deals with the problem of evaluating the effect of a cylindrical metallic cavity on the radiation of a planar longitudinally polarized Bessel beam launcher, as it could arise in applications related to microwave heating or plasma ignition. A full analytical model is developed to extract fundamental physics insight of the problem at hand. Full-wave numerical simulations by COMSOL multiphysics are used to validate the proposed model, showing fair agreement between simulations and theoretical predictions.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Millimeter-Wave Wideband Wide-Angle Scanning Proactive Conformal Phased
           Array Antenna

    • Free pre-print version: Loading...

      Authors: Junqi Cheng;Shaowei Liao;Wenjie Feng;Wenquan Che;Quan Xue;
      Pages: 660 - 664
      Abstract: Though conformal phased array antennas have better wide-angle scanning capability than their traditional planar counterparts do, their fabrication is generally complex. Therefore, this letter presents a millimeter-wave (mmWave) proactive conformal (PC) phased array antenna (PAA) formed by high-low alternate elements/subarrays to proactively modulate the array aperture, achieving wide-angle scanning and easy fabrication. A 1×6-element endfire high-gain low sidelobe level subarray is designed, based on which a 4×6-element PC PAA is implemented. The measured results show that the reflection coefficient of the fabricated prototype is mostly 18 dB, the endfire scanning gain is>15.5 dBi, and the 3-dB gain variation scanning range is>±60° with a peak up to ±68° within 24.25–29.5 GHz (19.5%).
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
  • Ultrabroadband RCS Reduction and Gain Enhancement of Patch Antennas by
           Phase Gradient Metasurfaces

    • Free pre-print version: Loading...

      Authors: Tianhu Zhang;Xiaoyan Pang;Han Zhang;Qi Zheng;
      Pages: 665 - 669
      Abstract: In this letter, a novel design based on phase gradient metasurfaces (PGMs) is proposed to reduce the radar cross section (RCS) and enhance the gain of patch antennas. The PGM unit consists of a cross-dipole and three square-dipole rings. The proposed antenna is composed of a conventional patch radiator and four surrounding sequential-rotated PGMs. On the one hand, an ultrabroadband RCS reduction is achieved due to the PGMs phase discontinuity deflects the signal away from the specular direction by the PGMs. On the other hand, a gain enhancement is achieved because the enlarged equivalent radiation aperture owing to the coupling effect between the PGMs and the patch. A prototype operating at Ku band is designed, fabricated, and measured. It is demonstrated that an over 6 dB RCS reduction is obtained from 9.31 to 28.22 GHz, and an average 1.5 dB gain enhancement is obtained within the working band of 14.2–15.5 GHz, which can be used in stealth platforms.
      PubDate: March 2023
      Issue No: Vol. 22, No. 3 (2023)
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 44.201.94.236
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-