Transverse Array Research Articles

Series Dual-Fed Continuous Transverse Stub Array With Enhanced Multibeam Operation Enabled by a Reflective Luneburg Lens

Series Dual-Fed Continuous Transverse Stub Array With Enhanced Multibeam Operation Enabled by a Reflective Luneburg Lens

“Co-coordination force” assisted rigid-flexible coupling crystalline polymer for high-performance aqueous zinc-organic batteries

Organic electrode materials (OEMs) have attracted substantial attention for aqueous zinc-ion batteries (AZIBs) due to their advantages in relieving resource and environmental anxiety. However, the potential of OEMs is plagued by their low achievable capacity and high solubility. Here, we have proposed a new concept of “co-coordination force” and designed a rigid-flexible coupling crystalline polymer that can overcome the abovementioned limitations. The obtained crystalline polymer (BQSPNs) with multiredox centres makes the BQSPNs exist intermolecular hydrogen bonds (HB) among -C=O, -C=N, and -NH and consequently exhibits transverse two-dimensional arrays and longitudinal π-π stacking structure. Additionally, in-situ FTIR, Raman, variable temperature FTIR spectra, and 2D nuclear overhauser effect spectroscopy (NOESY) well capture the existence and evolution process of HB during the electrochemistry reaction process of BQSPNs, uncovering the effect of HB in stabilizing the structure and promoting the reaction kinetics. As a result, the BQSPNs with rationally designed “co-coordination force” deliver a high capacity of 459.6 mAh/g and a stable cycling lifetime for more than 100,000 cycles at 10 A/g in AZIBs. Our results disclose the HB effect and provide a brand-new strategy for high-performance OEMs design.

A wideband and high‐gain switched‐beam antenna system using active frequency selective surface

AbstractAntennas using the active frequency selective surface (AFSS) can achieve fast beam‐scanning ability at a low cost. In this study, a switched beam antenna with a high gain and 360° coverage in the horizontal plane is proposed. Twelve columns of AFSS form a cylindrical cavity and are transmissive or reflective to the incident electromagnetic waves under the control of PIN diodes. Benefiting from a coaxial continuous transverse stub array placed at the cavity centre and using 4 units to generate a high gain omnidirectional radiation, the proposed antenna can realise a highly directive switched beam. An antenna prototype is designed, fabricated and measured. Results show that it achieves a |S11| < −10 dB bandwidth of 12.9% and is able to sweep its beam around the azimuth plane with a high gain up to 13.6 dBi at 5.8 GHz working frequency.

A dual‐band dual‐polarized shared‐aperture SIW slot antenna array with beam scanning

AbstractThis letter proposes a low‐profile dual‐band dual‐polarized (DBDP) substrate‐integrated waveguide (SIW) slot antenna array with beam scanning. By stacking the SIW transverse slot array (TSA) above the longitudinal slot array (LSA) in one aperture, two orthogonal polarizations are generated at two bands. To avoid the radiation slots of the LSA and the TSA from overlapping, the LSA is developed based on the proposed LSA unit whose collinear‐slot arrangement is realized by introducing metallized vias. Two planar parabolic reflectors based linear source generators (LSGs) are integrated to feed the shared‐aperture radiation array. By moving two independent SIW horns, the proposed antenna can obtain the steering angles of ±34° and ±27° at the central frequencies of 11.2 and 13 GHz, respectively. Two beams with orthogonal polarizations scan in the same plane. The simulated results have been validated by the experimental ones. The proposed antenna has low profile and is a potential candidate for satellite and wireless communications.

Research on performance of piezoelectric superimposed beam energy harvester under gyromagnetic excitation

In this paper, In order to make use of the rotating motion characteristics of the roller cage shoe structure in vertical shaft lifting guide device, a nonlinear gyromagnetic excitation piezoelectric superposition beam energy harvester with compact structure, non-contact and high energy harvester efficiency is designed. The nonlinear force between moving magnet and stationary magnet is used to transform the rotating motion of the roller cage shoe into the end vibration of the piezoelectric vibrator. In order to improve the utilization rate of the piezoelectric plate and the low-amplitude response sensitivity of the energy harvester, acrylic material is introduced to re-place the traditional metal substrate, the bottom piezoelectric vibrator is hinged with the end of the top piezoelectric vibrator, and the middle part of the piezoelectric vibrator ends are longitudinal-superimposed beam structure with chute connection. The structural parameters, gyromagnetic excitation properties and strength of the piezoelectric vibrator are optimized and analyzed through finite element simulation and experiments, and the longitudinal and transverse arrays of piezoelectric vibrators are designed. The effects of terminal connection mode, array spacing, array number and load resistance on the power generation performance of the energy harvester are investigated. The results show that when the number of vertical arrays is 8 layers and the array spacing is 1.5 mm, higher voltage output and vibration consistency are achieved. When the horizontal array is 7 groups and the load is 10 kΩ, the maximum output power of the energy harvester is 11.26 mW, which can realize the self-power supply to the wireless transmitting node.

A Sleeve-Based, Micromotion Avoiding, Retractable and Tear-Opening (SMART) Insertion Tool for Cochlear Implantation.

In conventional cochlear implantation, the insertion of the electrode array is strongly affected by the local anatomy and human kinematics. Herein, we present a concept for an insertion tool that allows to optimize the insertion trajectory beyond anatomical constraints and stabilizes the electrode array in manual implantation. A novel sleeve-based design allows the instrument to be compliant and potentially protective to intracochlear structures, while a tear-open mechanism allows it to be removed after insertion by simply retracting the tool. Conventional and tool-guided manual insertions were performed by expert cochlear implant surgeons in an analog temporal bone model that allows to simultaneously record intracochlear pressure, insertion forces and electrode array deformation. Comparison between conventional and tool-guided insertions demonstrate a substantial reduction of maximum insertion forces, force variations, transverse intracochlear electrode array movement, and pressure transients. The presented tool can be utilized in manual cochlear implantation and significantly improves key metrics associated with intracochlear trauma. The instrument may ultimately help improve hearing outcomes in cochlear implantation. The versatile design may be used in both manual cochlear implantation and motorized and robotic insertion, as well as image-guided surgery.

Quasiperiodic photonic crystal fiber [Invited

In the fields of light manipulation and localization, quasiperiodic photonic crystals, or photonic quasicrystals (PQs), are causing an upsurge in research because of their rotational symmetry and long-range orientation of transverse lattice arrays, as they lack translational symmetry. It allows for the optimization of well-established light propagation properties and has introduced new guiding features. Therefore, as a class, quasiperiodic photonic crystal fibers, or photonic quasicrystal fibers (PQFs), are considered to add flexibility and richness to the optical properties of fibers and are expected to offer significant potential applications to optical fiber fields. In this review, the fundamental concept, working mechanisms, and invention history of PQFs are explained. Recent progress in optical property improvement and its novel applications in fields such as dispersion control, polarization-maintenance, supercontinuum generation, orbital angular momentum transmission, plasmon-based sensors and filters, and high nonlinearity and topological mode transmission, are then reviewed in detail. Bandgap-type air-guiding PQFs supporting low attenuation propagation and regulation of photonic density states of quasiperiodic cladding and in which light guidance is achieved by coherent Bragg scattering are also summarized. Finally, current challenges encountered in the guiding mechanisms and practical preparation techniques, as well as the prospects and research trends of PQFs, are also presented.

HY5 inhibits lateral root initiation in Arabidopsis through negative regulation of the microtubule-stabilizing protein TPXL5.

Tight control of lateral root (LR) initiation is vital for root system architecture and function. Regulation of cortical microtubule reorganization is involved in the asymmetric radial expansion of founder cells during LR initiation in Arabidopsis (Arabidopsis thaliana). However, critical genetic evidence on the role of microtubules in LR initiation is lacking and the mechanisms underlying this regulation are poorly understood. Here, we found that the previously uncharacterized microtubule-stabilizing protein TPX2-LIKE5 (TPXL5) participates in LR initiation, which is finely regulated by the transcription factor ELONGATED HYPOCOTYL5 (HY5). In tpxl5 mutants, LR density was decreased and more LR primordia (LRPs) remained in stage I, indicating delayed LR initiation. In particular, the cell width in the peripheral domain of LR founder cells after the first asymmetric cell division was larger in tpxl5 mutants than in the wild-type. Consistently, ordered transverse cortical microtubule arrays were not well generated in tpxl5 mutants. In addition, HY5 directly targeted the promoter of TPXL5 and downregulated TPXL5 expression. The hy5 mutant exhibited higher LR density and fewer stage I LRPs, indicating accelerated LR initiation. Such phenotypes were partially suppressed by TPXL5 knockout. Taken together, our data provide genetic evidence supporting the notion that cortical microtubules are essential for LR initiation and unravel a molecular mechanism underlying HY5 regulation of TPXL5-mediated microtubule reorganization and cell remodeling during LR initiation.

Ultra-Low-Profile Continuous Transverse Stub Array for SatCom Applications

Modern K-/Ka-band satellite communications have become increasingly demanding in recent years with regard to the performance of the terminal antenna used in the link. These terminals should be high gain and broadband, as well as guarantee polarization diversity over a large field of view. A low profile is also highly desired to integrate the antenna system into a variety of moving platforms, such as aircraft and trains. An ultra-low-profile continuous transverse stub array is proposed here to tackle these challenges. The antenna array is realized in printed circuit board technology by adopting a contactless transition between the stacked-up layers without resorting to blind or buried vias. The proposed antenna is wideband (impedance matched within the 19–31 GHz band, i.e., ~50%) and provides multibeam radiation for polar angles as far as ±22.5°. The peak value of the gain is 19.7 dBi, and the maximum radiation efficiency equals 50%. Furthermore, the antenna array is combined with a dual-band polarization converter. The latter provides orthogonal circular polarization (CP) in two non-adjacent bands. The overall antenna system performs right- and left-hand CPs within the SatCom downlink and uplink in the K-/Ka-band, respectively. For each polarization, the axial ratio is below 3 dB over 9.47% and 4.42% fractional bandwidths, respectively.

C‐band frequency‐scanning continuous transverse stub array with high gain and low sidelobe level

A C-band substrate integrated waveguide based frequency-scanning continuous transverse stub (CTS) array with high gain and low sidelobe level (SLL) is presented in this paper. The newly suggested linear source generator (LSG) consists of a feeding probe, a main reflector, a sub-reflector, and two metal matching vias. By introducing one matching via on the left side of probe and another one on the right side of the sub-reflector, a broadband LSG is obtained to excite the CTS array with a wide scanning range. The operating mechanism of the two matching vias is analysed. In order to reduce SLL, a serial-fed array with asymmetrically distributed stub width is designed according to Chebyshev distribution for the first time. A prototype of 12-element array is designed, simulated and measured, and excellent agreements are achieved. The measured beam-scanning range is from −52° to 2° within the operating frequency of 5.6–8 GHz, in which |S11| is less than −10 dB. The maximum gain is 22 dBi and the SLL varies between −21 dB and −18.2 dB. The proposed design approach can be applied to other bands and other level distributions. The proposed frequency scanning array has great potentials in radar and detection systems.

Necklace-structured high-harmonic generation for low-divergence, soft x-ray harmonic combs with tunable line spacing.

The extreme nonlinear optical process of high-harmonic generation (HHG) makes it possible to map the properties of a laser beam onto a radiating electron wave function and, in turn, onto the emitted x-ray light. Bright HHG beams typically emerge from a longitudinal phased distribution of atomic-scale quantum antennae. Here, we form a transverse necklace-shaped phased array of linearly polarized HHG emitters, where orbital angular momentum conservation allows us to tune the line spacing and divergence properties of extreme ultraviolet and soft x-ray high-harmonic combs. The on-axis HHG emission has extremely low divergence, well below that obtained when using Gaussian driving beams, which further decreases with harmonic order. This work provides a new degree of freedom for the design of harmonic combs—particularly in the soft x-ray regime, where very limited options are available. Such harmonic beams can enable more sensitive probes of the fastest correlated charge and spin dynamics in molecules, nanoparticles, and materials.

A High-gain and Beam-scanning Variable Inclination Continuous Transverse Stub Array Antenna Based on Linear-gradient Stub at Ku Band

A High-gain and Beam-scanning Variable Inclination Continuous Transverse Stub Array Antenna Based on Linear-gradient Stub at Ku Band

Compact line source generator for feeding continuous transverse stub arrays

Abstract Based on a substrate integrated lens (SIL), a compact line source generator (LSG) for feeding continuous transverse stub (CTS) arrays with linear-polarized (LP) beam scanning and dual-polarized (DP) operations is presented in this paper. The SIL consists of metamaterial cells with different sizes being arranged as concentric annulus and is printed on the center surface of two substrate layers. The SIL can convert the cylindrical wave generated by the feed probe of SIW-horn to the planar wave for feeding the CTS array. This rotationally symmetric SIL can be used conveniently to design LSG for feeding CTS arrays with the continuous beam scanning and DP operations, which has been verified by the fabrications and measurements. By simply rotating the SIW-horn along the edge of SIL, the 10-element LP-CTS array obtains a measured beam scanning range of ±35° with the highest gain of 20.6 dBi. By setting two orthogonal SIW-horns at the edge of the proposed SIL, the nine-element DP-CTS array with orthogonal radiation stubs is excited. The DP array obtains the gain of 20.3 dBi at the center frequency with the isolation of 28 dB and the cross-polarization level <−25 dB.

On the Use of Ridge Gap Waveguide Technology for the Design of Transverse Stub Resonant Antenna Arrays.

This paper presents some considerations on the design of a novel antenna consisting of the combination of a transverse stubs (TS) array excited by Ridge Gap Waveguides (RGWs), as well as a discussion of the experimental results obtained from a prototype that was manufactured and measured. A combination of Continuous Transverse Stubs (CTSs) is used as the starting point. Subsequently, the CTSs are modified to include some metallic blockers that split each CTS into a combination (array) of shorter TSs. This is performed in order to excite each individual TS column using a different RGW; thus, ensuring a close to uniform field distribution in the transverse plane of the TS arrays. Hence, the directivity of the antenna is increased. As a series-feed configuration is considered, the antenna keeps a resonant behaviour, having a narrow-band response. A Corporate Feeding Network (CFN) using the aforementioned RGW technology placed in the same layer as the rest of the antenna is included in the design. The radiating area of the antenna is, finally, with a simulated peak gain of 26.2 dBi and a Side Lobe Level (SLL) below −13 dB. A prototype is manufactured and tested. The simulated and measured radiation patterns maintain similar shapes to those of the simulations, with very similar angular widths in both main planes, although the frequency corresponding to the highest directivity changes to 31.8 GHz. A matching bandwidth of 517 MHz and a gain of 24.5 is, finally, achieved at that frequency.

A Low-Profile and Beam-tilted Continuous Transverse Stub Array Antenna at W-band

This paper presents a low-profile, high gain, beam-tilted continuous transverse stub (CTS) array antenna at W-band. The antenna compromises 32 radiating slots and is fed by a parallel plate waveguide (PPW) network with a linear source generator. To deflect the outgoing beam, the principle of linear array scanning is adopted to design inverted T-type structure in each stub to introduce wave path difference. PPW network allows the antenna to obtain lower profile compared to other transmission lines. The design procedure, and the antenna characterization are described. The main beam of the antenna is titled 12 degree in H-plane. The simulation and measured results show that this antenna achieves peak gain of 32.4 dB and a 12 degree beam tilt angle at 99GHz. S11 parameters of the antenna is less than -10 dB in a broadband from 96 GHz to 103 GHz. This antenna has an advantage of miniaturization over other high-gain antenna solutions. The promising performance of this proposed CTS antenna reveals the possible candidate for Millimeter wave (MMW) telecommunication applications.

Design of Compact Transverse Slot Array Antenna Using Corrugated H plane Horn

Design of Compact Transverse Slot Array Antenna Using Corrugated H plane Horn

Planar Dual-Polarization Bidirectional Multibeam Array Antenna for Millimeter-Wave Applications

A millimeter-wave (mm-wave) dual-polarization bidirectional multibeam array antenna based on substrate integrated waveguide (SIW) technology is presented in this article, which can generate 16 bidirectional radiation beams with two orthogonal linear polarizations. The proposed dual-polarization bidirectional multibeam array antenna, based on a new configuration, consists of two transverse slot array antennas (TSAAs), two longitudinal slot array antennas (LSAAs), and two dual-layer <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8 \times 8$ </tex-math></inline-formula> Butler matrices (BMs). To realize dual polarizations, a new type of TSAA is designed and combined with a conventional LSAA. For the purpose of bidirectional radiation, two types of dual-polarization array antenna (DPAA), which are realized by combining different arrangements of the TSAA and the LSAA, is composited. In addition, a dual-layer <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8 \times 8$ </tex-math></inline-formula> BM is developed, which can excite both the TSAA and the LSAA and generate dual-polarization bidirectional multibeam. Finally, the prototype of the planar dual-polarization bidirectional multibeam array antenna is fabricated, measured, and discussed. The measured results satisfactorily validate the simulated results.

Wireless communication applications of the variable inclination continuous transverse stub array for Ku‐band applications

A wideband and continuous beam steering variable inclination continuous transverse stub antenna array is presented in the communication. The proposed antenna consists of a continuous transverse stub (CTS) array and a line source generator (LSG). These two parts are designed and optimized separately. The LSG structure is generated by a Pillbox transition. The CTS array is composed of 20 radiating slots and is fed by a corporate-feed network. The corporate-feed network adopts a series-parallel hybrid structure to realize lower profile and high-efficiency performance. The relative rotation movement between the CTS array and the LSG generates a phase gradient on the radiation part such that the proposed antenna can obtain a continuous beam in the upper hemisphere. Based on the array synthesis encryption sampling technology theory, the relationship between the mechanical rotation angle and the beam direction is analysed and obtained. To validate the antenna concept, the antenna is fabricated and measured. The simulation and measurement results are in good agreement. Through the rotation of the CTS array, the designed antenna achieves a ±56°scan. The measured results show that the array can achieve an impedance bandwidth of 16% in Ku-band at the centre frequency of 12 GHz with 67% aperture efficiency. The proposed antenna has the characteristics of low profile, high efficiency, large coverage, and wideband, which is well suited for mobile satellite communication.

Multiband isolator based on a coplanar metaline

This study presents for the first time the feasibility of a coplanar isolator using YIG material for applications in the Ku, K and Ka bands. The proposed structure is an asymmetric coplanar waveguide with a transverse array of unopened slots etched on a ground plane. Such structures are characterized by several cut-off frequencies on the transmission parameters. With a low dc magnetic field of 72 kAm−1 applied along with the slots, significant nonreciprocal effects greater than 20, 19 and 29 dB are obtained at 13.95, 23.39 and 39.61 GHz, respectively. The proposed structure can be used as a multiband isolator for microwave applications. The low biasing field of this multiband isolator and its compactness (88 mm2) are its main advantages, which makes this structure particularly suitable for integration.

Tailoring multi-singularity structure induced by a focused radially polarized beam

A structured optical field with controllable three-dimensional intensity and multiple polarization singularities is demonstrated by utilizing a combination of a radially polarized (RP) beam, a designed phase mask, and a high numerical aperture lens. Owing to the tight focusing property of RP beams as well as the interference of multiple linearly polarized non-coplanar plane waves, various lattice-like optical structures can emerge at the focal plane with multiple structured singularities in the transverse plane and optical needle array along with propagation. Compared with recently proposed phase and polarization engineering methods with spatial light modulators, the method presented here is convenient and flexible, and can easily realize the generation of V-point and C-point lattices. More importantly, a structured longitudinal field, namely, an optical needle array, with steerable positive and reverse energy flows may be extensively applied in multi-particle acceleration and trapping, optical microscopes, and second-harmonic generation.