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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • GaN HEMTs
  • Power amplifier
  • Broadband power amplifier
  • SC band
  • Power combining
  • concentrated capacitive load
  • distribution of the complex current at the antenna
  • broadband antenna
  • standing wave voltage factor
  • antenna gain factor
应用领域
  • Electronic Science and Technology
机构单位
  • Oles Honchar Dnipro National University
  • University of Tehran
  • Gdansk University of Technology
  • V. N. Karazin Kharkiv National University
  • Reykjavik University
244 条数据
?? 中文（中国） ▾

  • [IEEE 2018 Iranian Conference on Electrical Engineering (ICEE) - Mashhad (2018.5.8-2018.5.10)] Electrical Engineering (ICEE), Iranian Conference on - Design and Implementation of Broadband Solid State SC-Band High Power Amplifier

    摘要： This paper presents the design and fabrication of a broadband high power amplifier from 2 to 6 GHz. The high power amplifier is implemented by combining several medium power GaN technology amplifiers to achieve 50 dBm output power. The architecture of the SC-band power amplifier consists of four power-lines, including a high power amplifier and a medium power amplifier as the input driver amplifier. Moreover, power combiners are used at the output of these lines. The designed power amplifier is then fabricated on a synthetic substrate for both high and low power sections. The measurement results show that the proposed design achieves 10 % to 28 % power added efficiency and 48 dBm to 51 dBm output power from 2 to 6 GHz.

    关键词： GaN HEMTs,Power amplifier,Broadband power amplifier,SC band,Power combining

    更新于2025-09-10 09:29:36

  • [IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Linear to Circular Polarization Conversion of Terahertz Wave Using Metallic Helix Array

    摘要： We developed a 2D array of 3D metallic helix which converts linearly polarized terahertz (THz) wave into circularly polarized THz wave and acts as a broadband THz wave polarizer. It covers the frequency range from 140 GHz to 250 GHz, close to one octave. We made two different arrays which consist of left-handed and right-handed metallic helices and we confirmed that these arrays change the linearly polarized THz wave into right-hand and left-hand circularly polarized THz wave respectively.

    关键词： terahertz wave,metallic helix array,broadband polarizer,polarization conversion

    更新于2025-09-10 09:29:36

  • Pressure-Induced Broadband Emission of 2D Organic-Inorganic Hybrid Perovskite (C <sub/>6</sub> H <sub/>5</sub> C <sub/>2</sub> H <sub/>4</sub> NH <sub/>3</sub> ) <sub/>2</sub> PbBr <sub/>4</sub>

    摘要： 2D Ruddlesden–Popper halide perovskites, which incorporate hydrophobic organic interlayers to considerably improve environmental stability and optical properties diversity, have attracted substantial research attention for optoelectronic applications. The burgeoning broad emission arising from exciton self-trapping of 2D perovskites shows a strong dependence on a deformable structure. Here, the pressure-induced broadband emission of layered (001) Pb-Br perovskite with a large Stokes shift in the visible region is observed by finely improving lattice distortion to increase exciton–phonon coupling under hydrostatic pressure. Band gap narrows ≈0.5 eV under modest pressure, mainly due to the large compressibility of the orientational organic layer, confirming that the bulky organic cations notably influence the structure and, in turn, the various properties of materials. Sequential amorphization of the organic and inorganic layer is confirmed by high pressure Raman and X-ray diffraction measurements, suggesting the particularity of layered crystal structures. The mechanism constructed here offers a new route for tuning the optical properties of 2D perovskites.

    关键词： broadband emission,band-gap narrowing,pressure,perovskites,amorphization

    更新于2025-09-10 09:29:36

  • [IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu, China (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - A Miniaturized Cavity-Backed Sector Antenna with Bandwidth Enhancement for UAV Applications

    摘要： A novel miniaturized cavity-backed sector antenna for VHF (Very High Frequency) applications is proposed in this paper. The proposed antenna is composed of two symmetrical meandering lines, a planar double-sector patch and a U-shaped backed-cavity. Two symmetrical meandering lines are used to achieve size reduction by connecting four ends of the double-sector patch. Moreover, a U-shaped backed-cavity is employed to improve directivity and achieve better gain. The proposed has a very compact size of 36cm×40cm×25cm (0.13λ0×0.15λ0×0.09λ0), which could bring considerable benefits for the design of UAV system. Simulated results show that the antenna achieves a return loss better than 10dB over 31% impedance bandwidth. The gain of this antenna is more than 2dBi. With features such as small size, wide bandwidth and good directivity, the proposed antenna can meet the demanding requirements to the application of UAV airborne system.

    关键词： bandwidth enhancement,sector antenna,miniaturization,VHF antenna,broadband antenna

    更新于2025-09-10 09:29:36

  • Polarization-independent and super broadband flat lens composed of graded index annular photonic crystals

    摘要： In this paper, we propose two types of all-dielectric polarization-independent graded index annular flat lens with a wide operating frequency range. The lenses are composed of two-dimensional triangular and square lattice photonic crystals with circular silica (SiO2) rods in the air. We assume in both square and triangular structures, the lenses are obtained by making air holes within each dielectric rod and we consider that the outer radius of the created annular rods are maintained constant while the size of the inner air holes varies along the transverse direction whose the air holes variation follow linear and parabolic function. The graded structures are made in such a way that the modulus of the refractive index is biggest at the center and decreases toward the edges. The optical properties and the physical background of the polarization-independent focusing mechanism are studied in frequency and spatial domains, using plane wave expansion and finite-difference time-domain methods. Our numerical results show that, through an appropriate set of design, the deigned lenses are able to focus the light regardless of polarization for a wide frequency range into approximately same focal length in which difference between focal distance of TE and TM polarization modes stays below λ/4. Compared to previously polarization-independent designed photonic crystal based lenses, our proposed structures work under much wider frequency range. Also, in contrast with most of the graded structures, our graded lens are made without altering the lattice constant along optical axis or transverse to optical axis. Moreover, the design approach is restricted to use of silica and non-use of more complicate materials such as liquid crystals, plasma, and the like. Thus, the designed systems can be constructed easier relative to the previously designed lenses.

    关键词： Graded index annular photonic crystals,Optical beam focusing,broadband frequency lens,Polarization-independent lens

    更新于2025-09-10 09:29:36

  • Preparation and electromagnetic attenuation properties of MoS2–PANI composites: a promising broadband absorbing material

    摘要： As an ideal electromagnetic (EM) wave absorber, it is prone to possess lightweight, thin matching thickness, broad absorption bandwidth and strong absorption performance. In this work, MoS2–PANI composites were prepared by situ chemical oxidative polymerization method, and the crystal structure, morphology, composition and EM properties were characterized. The microwave absorption properties of MoS2–PANI composites could be tuned by changing the PANI content to reach the best impedance match. The minimum reflection loss (RL) value of MoS2–PANI was ? 40.79 dB at 14.01 GHz with the thickness of 2.0 mm, and the maximum effective absorption bandwidth was 5.02 GHz ranging from 11.88 to 16.90 GHz with a thickness of 2.0 mm. Moreover, the RL value of MoS2–PANI composites could reach under ? 10 dB in a wide frequency range of 4.74–18 GHz with a thickness of 1.5–4.5 mm. In particular, the 3 mm wave attenuation properties of MoS2–PANI composites were investigated for the first time, and the maximum attenuation value reached 15.45 dB. As a result, MoS2–PANI composites are promising to be excellent EM wave absorption materials in broadband.

    关键词： Electromagnetic wave absorption,Broadband absorbing material,MoS2–PANI composites,Chemical oxidative polymerization,Impedance match

    更新于2025-09-10 09:29:36

  • Independent excitation of inhomogeneous energy density driven instability by electron density gradient

    摘要： In this work, we report an experimental observation of the inhomogeneous energy density driven instability (IEDDI) independently excited by the electron density gradient. This was achieved using a novel design which could generate a controllable electron density gradient, while the self-consistent electric ?eld accompanied with the electron density gradient can be simultaneously compensated. Broadband wave mode in the ion cyclotron frequency range was excited, which was further experimentally identi?ed as the IEDDI. This result suggests that the IEDDI can be independently excited by the electron density gradient, which could be extended to explain the satellite observations of the broadband extremely low frequency waves in the auroral plasmas where the strong plasma density inhomogeneities exist.

    关键词： IEDDI,auroral plasmas,ion cyclotron frequency,electron density gradient,broadband wave mode

    更新于2025-09-10 09:29:36

  • COMPACT BROADBAND END-FIRE ANTENNA WITH METAMATERIAL TRANSMISSION LINE

    摘要： A broadband end-?re antenna loaded with magneto-electro-dielectric metamaterial (MED-MTM) is presented in this paper. Based on a planar printed structure, many periodic structures are investigated in antenna design. The metal patch is embedded with a C-shaped complementary split-ring resonator (CSRR) array, and many cross slots are etched on the ground plane. The zeroth-order resonance (ZOR) and ?rst-order resonance (FOR) can be excited. As a result of electromagnetic coupling e?ect, the C-shaped patch and ground plane compose metamaterial transmission line (MTL). For potential applications, the broadband and end-?re antenna can work with a 53.5% (3.81–6.59 GHz) impedance bandwidth. The proposed antenna achieves size reduction, gain improvement and bandwidth enhancement.

    关键词： transmission line,end-?re antenna,ZOR,FOR,CSRR,metamaterial,broadband

    更新于2025-09-10 09:29:36

  • Full W-Band GaN Power Amplifier MMICs Using a Novel Type of Broadband Radial Stub

    摘要： In this paper, we describe the design of the first reported full W-band (75–110 GHz) power amplifier (PA) monolithic microwave integrated circuits (MMICs) based on gallium nitride technology. The discussed MMICs come in two versions. Over a bandwidth (BW) of 70–110 GHz, the three-stage PA can deliver, on average, 25.6 dBm with a power-added efficiency (PAE) of 6.5%, while the four-stage PA is able to generate 27 dBm with a PAE of 6.1%. A peak output power of 28.6 dBm is achieved at 80 GHz with a PAE of 8.6%, which corresponds to a power density of 2.6 W/mm. The significant BW was achieved partially by incorporating a novel type of broadband radial stub into the design, which can provide nearly a twofold rejection-BW improvement over the conventional version. To the best of our knowledge, no other solid-state circuit can deliver such power levels over the complete W-band.

    关键词： monolithic microwave integrated circuit (MMIC),Broadband,power amplifier (PA),high-electron-mobility transistor (HEMT),W-band (75–110 GHz),radial stub,gallium nitride,millimeter-waves (mm-waves)

    更新于2025-09-09 09:28:46

  • [IEEE 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Espoo, Finland (2018.8.27-2018.9.1)] 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Compact Broadband Dipole Antenna with Split Ring Resonators

    摘要： A compact broadband low-profile dipole antenna with split ring resonators (SRRs) is presented. The antenna is composed of a conventional dipole element and two SRRs. Each arm of the printed dipole is enclosed by a printed SRR to provide the favorable electromagnetic environment for coupling. Three modes are generated, which interact together to provide broadband characteristics, covering 1.45 GHz to 2.49 GHz (|S11| < ?10 dB bandwidth of 52.79%). The antenna is computationally demonstrated to have broadband characteristics and stable gain with symmetric radiation patterns. The compact antenna with overall dimensions of 10.2 mm × 74.6 mm × 0.508 mm (0.067λo × 0.489λo × 0.0033λo at 1.97 GHz) has a radiation efficiency > 90%. The compact size, simple structure, and stable radiation properties of the antenna increase its suitability for many wireless communication applications.

    关键词： broadband,split ring resonators,dipole antenna,compact,wireless communication

    更新于2025-09-09 09:28:46