A 3-D-printed Luneburg lens with a novel simplified geometry is presented. The rod-type structures are employed as the unit cell of gradient-index material to realize required permittivity distribution in lens. prototype designed Ka-band manufactured successfully by using commercial 3-D printing facility. substrate-integrated waveguide fed magnetoelectric (ME)-dipole antenna endfire radiation introduced feed for due its wideband performance and compact configuration. By combining set...

In this letter, electromagnetic band-gap (EBG) structure is used to reduce the radar cross section (RCS) of patch array antenna. The proposition method based on high impedance characteristic mushroom-like EBG structure. basic antenna designed with a central frequency 5.0 GHz while replacing substrate band in which RCS reduced significantly can be adjusted by parameters EBG. backward as much 10 dB compared that conventional antenna, and degradation performance not significant.

A dual-mode composite microstrip line (DMC-MSL) is reported in this paper for the purpose of designing dual-band antennas and devices with a large frequency ratio. The metallic strip conventional MSL replaced substrate integrated waveguide (SIW) arranged into thin dielectric laminate, which leads to that two modes operating different bands, i.e., quasi-TEM mode TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> -like mode, can propagate...

A modified topology of the 2-D multibeam antenna array fed by a passive beamforming network (BFN) is proposed introducing two sets vertical interconnections into conventional configuration. Different from traditional design, new structure can be integrated multilayered planar substrates conveniently, which has advantages low loss characteristics, ease realization, and fabrication cost for millimeter-wave (mmWave) applications. 4×4 that generate 16 beams then designed, fabricated, measured in...

3-D printed air-filled waveguide fed horn antenna arrays are investigated in the Ka-band. Pyramidal E-plane antennas with a small size introduced as radiating element to improve bandwidth and radiation characteristics of array. Commercial direct metal laser sintering technology is applied print structure whole piece. Excellent operating performance including wide impedance bandwidths 25.8% 23.8% for <; -10 dB, gains up 27.5 33.8 dBi variation less than 1.5 dB over band efficiencies around...

Unmanned aerial vehicle (UAV) communications have been considered as one of the promising technologies to support numerous applications in fifth and sixth generations wireless networks. A deep understanding propagation channel is necessary for design communication systems. three-dimensional (3D) wideband non-stationary geometry-based stochastic model (GBSM) proposed UAV multiple-input multiple-output (MIMO) channels this paper. The GBSM considers both line-of-sight (LoS) non-LoS (NLoS)...

A novel fixed-frequency beam-scanning leaky-wave antenna (LWA) based on a period-reconfigurable structure is presented. Operating at 5 GHz, the consists of slotted substrate integrated waveguide and 54 electrically small patches. Each patch element etched with two dumbbell-shaped slots, its operating state can be flexibly controlled by biasing p-i-n diode parasitic strip. An ideal array model employing isotropic point sources used for analysis scanning mechanism, which new method suppressing...

A codesigned hepta-band antenna with a large frequency ratio is presented by using mode-composite method. The method based on an idea that apart from quasi-TE10 mode transmitting in substrate integrated waveguide (SIW) structure at millimeter-wave frequencies, additional radiation modes of the wire antennas can be excited simultaneously outer surface well-designed SIW microwave frequencies much lower than its cut-off frequency. In this design, combination meander section and L-shaped are...

A novel substrate integrated waveguide (SIW) fed horizontally polarized endfire magnetoelectric (ME) dipole antenna composed of an open-ended SIW with broad walls vertical to substrates and a pair electric dipoles realized by four metallic patches is proposed. Simple configuration excellent performance including impedance bandwidth 46.5%, stable gain around 6 dBi, symmetrical cardioid radiation patterns low backward cross polarizations are achieved. An 90° twist in three-layered implemented...

A novel circularly polarized (CP) complementary source antenna with endfire radiation is proposed in Ka-band. With the existence of two antipodal notches etched at edges broad walls an open-ended substrate-integrated waveguide, orthogonal electric field components radiated from equivalent magnetic current, and currents separately can be excited simultaneously. The magnitude phase differences between filed controlled effectively by properly tuning dimensions notches. operating mechanism...

A millimeter-wave (mmW) low-profile wideband magneto-electric (ME) monopole antenna with the vertically polarized endfire radiation is presented by combining a pair of top-loaded electric monopoles thin open-ended substrate integrated waveguide (SIW) extended lower broad wall. The has profile 0.19 wavelength at center frequency operating band, wide bandwidth 60.7% (from 23.5 to 44 GHz) covering all fifth-generation (5G) mmW bands in Ka-band, stable gain around 7 dBi, and tilted pattern. Then...

A reliable vehicle-to-vehicle (V2V) channel model is necessary for intelligent transportation systems (ITSs) design. Due to the high mobility of vehicles and low heights antennas, line-of-sight (LOS) propagation paths in V2V communications are more likely be obstructed by large such as buses. Therefore, it worthwhile conduct in-depth investigations on line-of sight (OLOS) channels caused vehicle obstructions. In this paper, actual measurements with obstructions at 5.9 GHz band conducted....

T lymphopenia, occurring in the early phase of sepsis response to systemic inflammation, is commonly associated with morbidity and mortality septic infections. We have previously shown that a sufficient number cells required constrain Toll-like receptors (TLRs) mediated hyperinflammation. However, underlying mechanisms remains unsolved. Herein, we unveil CD4+ engage MHC II macrophages downregulate TLR pro-inflammatory signaling. show further direct contact between CD4 molecule or ectodomain...

In this letter, a dual-band and dual-polarization capacitive-fed slot patch antenna is investigated. The proposed can operate at 1.575 GHz for Global Positioning System 2.4 Wi-Fi system with the corresponding polarizations. A 90 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> hybrid coupler chip was used to excite right-hand circular polarization required optimum GPS performance. For high frequency band, pair of linearly polarized...

A novel dipole array loaded substrate integrated H-plane sectoral horn antenna with a simple three-layered geometry is proposed. The into two extra dielectric strips connected to the top and bottom edges of aperture. Both aperture are effectively radiated together. wide impedance bandwidth 44% for |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB that can cover entire Ka-band verified by fabricated prototype. Additionally,...

A novel kind of leaky-wave antenna (LWA) array with a power-recycling feeding network is proposed for radiation efficiency improvement. The constructed by two kinds substrate-integrated waveguide LWAs different periodic slots. One the LWA designed to work on fundamental (m = 0) wave and radiates in forward direction. other one -1th -1) spatial harmonic backward nonradiated power at end directly fed into (adjacent) reverse Therefore, reversed can compensate opposite direction LWAs, result...

A novel millimeter-wave aperture-coupled magnetoelectric (ME) dipole antenna with a low-profile metallic geometry is proposed based on the 3-D printing technology. An impedance bandwidth of 53.7%, gain up to 10.8 dBi, and stable unidirectional radiation patterns cross polarization less than -38 dB are achieved by antenna. Its operating mechanism design process studied in detail as well. In order widen fullcorporate H-plane air-filled waveguide feed network, wideband stepped T-junction...

A millimeter-wave high-gain dual-polarized antenna array with an enhanced bandwidth is presented. An innovative air-filled differential feeding cavity loaded a short-ended cross-shaped waveguide investigated to serve as the feed network and mode splitter simultaneously of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\,\,\times2$ </tex-math></inline-formula> subarrays. Wideband characteristics compact...

Obtaining angle-of-arrival (AOA) information is of great significance to improve the performance communication systems. Real-time AOA recognition can reduce complexity beamforming design for massive multiple-input multiple-output (MIMO) systems, and be used construct an outer precoder optimize system rate. However, vehicular communications, will change with environment positions vehicles, it difficult obtain accurate in real-time. Therefore, a fast method needed adapt rapid changes channels....

A novel Ka-band spoof-surface-plasmon-polaritons (SSPPs) Butler-matrix-fed multibeam patch antenna array is proposed. An SSPPs-fed single-layered microstrip with suppressed cross-polarization investigated acting as the radiator. By using SSPPs etched on both sides of a substrate, 3 dB coupler, crossover, two phase shifters, and vertical interconnection compact geometries promising performance are designed investigated. connecting devices together, an Butler matrix realized, whose topology...

In this article, the deception attack detection problem is studied in scenarios involving multisecurity level transmission channels. Powerful attackers can construct stealthy attacks by exploiting data from reliable and unreliable From perspective of correlation, we develop three schemes with different resource consumption. First, a fully security channel utilized to establish innovation-based time-varying which triggers residual covariance variation under attacks. Second, noise-encryption...