Several configurations of multi-beam reconfigurable THz antennas based on graphene have been investigated. Two modulation mechanisms graphene-based antenna are introduced, one is the reflector-transmission window model, and other reflector-director model (Yagi-Uda antenna). The main parameters, such as beam direction, resonance frequency, peak gain, front-to-back ratio proposed can be controlled by adjusting chemical potentials in antenna. Moreover, this paper provides an easy way to obtain...

Object detectors based on convolutional neural networks (CNNs) have been widely deployed in industrial production for safety detection to guarantee the security of workers, and helmet is one most crucial application scenarios. In this article, we first consider insufficiency existing largest open-source dataset SHWD introduce our which contains various scenarios that are lacking former dataset. addition, reconsider sample selection method Yolo series propose a hierarchical positive (HPSS)...

A 16 ×16 -element reconfigurable transmitarray antenna (RTA) is designed and experimented in this paper. The proposed element consists of a receiving (Rx) structure transmitting (Tx) structure. rectangular patch with C-shaped probe-fed as the Tx to obtain characteristics broad bandwidth low loss, where U-shaped slot Rx simple Two PIN diodes are symmetrically integrated on feeding line. By turning them ON or OFF simultaneously, induced current directions reversed, thus achieving two phase...

A low-profile wide-angle reconfigurable transmitarray antenna (RTA) is proposed in this communication. This RTA consists of a feeding antenna, phase transforming lens, and 1 bit phase-reconfigurable transmitting (PRTA). The composed 12 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times12$ </tex-math></inline-formula> slot array fed by 36-way waveguide power divider, which possesses the characteristics...

A 2-bit electronically planar reconfigurable array antenna (PRAA) at Ku band is presented in this letter. The proposed PRAA element employs the hybrid phase control method to realize reconfiguration of its radiation structure and feeding structure. designed as a O-slot patch integrated with two p-i-n diodes obtain 1-bit quantization. To ability, digital shifter additional 90° shifting. Then, 4 × 4-element subarray simulated, which fed by using an asymmetric 16-way stripline network. 2-D beam...

Magnetic matchstick micromotors with two motion modes that can be reversibly switched <italic>in situ</italic> were synthesised.

A novel Ku-band pattern-reconfigurable array antenna is designed and experimentally tested, which able to electronically form various radiation patterns, including a single pencil beam, dual beams, quad fan beam. It consists of 4 × probe-fed O-slot patch elements. Two p-i-n diodes are integrated on the each element, by alternatively activating one diodes, direction excitation current reversed. Hence, element generate two-phase states with 180° phase difference. In order properly excite...

In this letter, a 1-bit wide-angle and multipolarization beam-scanning reconfigurable reflectarray antenna (RRA) is designed, fabricated, measured. The proposed RRA element consists of square base, circular turntable, three butterfly staircases with different heights based on three-dimensional all-metal structure. reflected phase orthogonal linear polarization reconfigurability can be achieved by rotating the element. Then, an prototype 26 × rotational elements are which fed <italic...

A novel differential filtering antenna with high selectivity is proposed. The mainly composed of three different-size patches, a slot, pair feeding lines, and line resonator. An air gap adopted to improve the impedance bandwidth performance. resonator helps generate common-mode (CM) rejection. Owing parasitic concave convex performance are enhanced. patch affects lower band-edge while influences upper selectivity. In addition, frequencies two radiation nulls can be controlled independently...

Abstract Large‐scale synthesis of micromotors powered by visible light and pure water is challenging, yet crucial for practical applications. Herein, a new method large‐scale uniform Janus ZnO reported, partially encapsulating microsphere within polysiloxane microsphere. The resulting autonomously move under in at speeds up to 15 μm/s. shapes these are readily tuned adjusting the chemicals used synthesis, influence on quantified. Moreover, interesting collective behaviors, such as formation...

Inorganic particles with photocatalytic properties are excellent candidates for the fabrication of micromotors. To achieve self-propulsion, geometric and chemical symmetries inorganic should be broken. However, synthesis micromotors different remains challenging. In this paper, a simple method is proposed to prepare rod-shaped patches, leading distinct symmetries. The composed zinc oxide (ZnO) microrods partially patched polysiloxanes at positions. patches can roughly regulated by varying...

Abstract Graphene is a promising material for terahertz (THz) reconfigurable devices due to the tunability of surface conductivity. Here, graphene‐based THz miniaturized‐element tunable band‐stop frequency selective (FSS) demonstrated. The proposed FSS unit cell consists convoluted metallic strips with graphene embedded between adjacent strips. center resonance stop band shows an obvious blue shift from 1.76 2.56 when increasing chemical potential 0 0.5 eV. Particularly, design leads...

GPM based on THGEM has shown its competitive strength compared to the conventional PMT, especially in low background research such as dark matter detection. A kind of made from PTFE, named PTFE-THGEM, is developed for be used CDEX. The PTFE a lot advantages level radioactivity. PTFE-THGEM was tested at room and cryogenic temperature. It high gain different gases shows good stability single reached 112 117 K. penning effect also discussed this paper explain "abnormal" phenomena gases.

Due to the wide bandwidth of 5G systems, multiple antennas are usually required cover entire frequency band in practical applications. Finding a single antenna structure that covers communication has been focus application. This paper proposes combined consisting an axially corrugated horn and orthomode transducer (OMT), which can range system-24-50GHz. The OMT is used for mode separation, its common port uses circular quad-ridge waveguide achieve UWB high isolation. aperture design with...

In this paper, a tri-band impedance transformer (TBIT) using coupled line and dual-band to is proposed, which can transform frequency-dependent complex impedances real-value impedance. order explain how determine circuit parameters, closed-form equations are derived in detail. Based on the TBIT, compact T-junction power divider (TTPD) designed. This TTPD works at three different frequencies with independent controllable division ratios. Simple steps design listed. To demonstrate validity of...

A dual-polarization ultra-wideband(UWB) horn antenna is proposed in this paper. This uses quad-ridge structure to achieve broadband and characteristics. In order reduce the overall weight, there no metal wall part of ridge which has little effect on electric field removed. The measured VSWR results are less 2 1.5-18GHz usable frequency band 1-20GHz. port isolation than -25dB, gain 10dB Typ. cross polarization -20dB. weight around 0.56 Kg around. been processed applied systems.

This manuscript presents a single-layer quadruple-band millimeter-wave antenna for 5G application. Its upper layer is made up of hexagonal patch fed by 50 Ω microstrip line. By etching two symmetric split-ring slots on the patch, it allows to operate at three frequencies which are 27.5 GHz, 44.6 and 50.7 GHz. Then, pair L-shaped branches coupled both sides line realize resonance point 36.7 The gains these four respectively 6.4 dBi, 7.6 9.2 7.1 dBi while -10 dB impendence bandwidth cover 27.2...

The severe capacity loss of tin-based anodes restricts their use in lithium batteries (LIBs). To enhance tin anode cycle stability, tin-antimony double-discharge were designed. Additionally, by ball milling, oxide, and flake graphite cycling-stable composites created. stacked buffers volume rise enhances electrical conductivity, cyclic specific capacity, rate performance. After 400 cycles, the oxide-graphite shows good cycling (480[Formula: see text]mAh[Formula: text]g[Formula: text]). Ball...

This paper proposed a dual-polarized broadband horn antenna for mm-wave 5G application. The operating frequency of the in this is 18 to 40GHz. with VSWR<;2, isolation<;-20dB, gain>10dB and HPBW>20° presented, radiation patterns maintain good symmetry full band. And has been tested used practical applications.

A Ku-band planar 1-bit phase-reconfigurable antenna element is proposed in this paper. The consists of three laminates, two bondply layers, and five metallic where a probe-fed O-slot patch, with compact stripline feeding line designed. Two PIN diodes are symmetrically integrated on the patch. By, respectively, activating these diodes, able to generate phase states resolution (0°/180°). simulated 1-dB gain bandwidth from 11.8 GHz 14.8 GHz, at 12.5 3.95 dBi while radiation efficiency 79.4%....

In the China Dark matter EXperiments (CDEX), HPGe is main target detector while liquid Ar used to provide low temperature working environment for detector. meantime, as a scintillation detector, it also served veto Gaseous avalanche Photomultipliers (GPMT) one of most promising candidates readout light from Ar, that is, 128nm Vacuum Ultraviolet (VUV). Compared with PMT, GPMT has many advantages, such lower radioactivity. A kind researched in this study based on THGEM coated CsI. The...

This paper proposes an ultra-wideband discone antenna. The operation frequency band is 1-18GHz. antenna can be regarded as the deformation of bicone size disk structure affects radiation pattern and distance between cone impedance matching. VSWR measurement results are less than 2.3, gain 1-8dB has stable omnidirectivity in frequency. proposed been applied many systems.