- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Design of 2 to 18?GHz balanced antipodal Vivaldi antennas using substrate-integrated lenses
摘要： Conventional balanced antipodal Vivaldi antennas (BAVAs) normally have deep ripple levels in E-plane mainlobe region and significant H-plane beamwidth variation over upper frequency band, which are drawbacks for ultra-wideband (UWB) applications. To overcome these issues, this paper introduces two types of lens configurations in front of BAVA. A gradient-index semi-cylindrical lens and a cylindrical lens are employed to improve ripples depth of E-plane mainlobe and broaden H-plane beamwidth, respectively. Both these lenses and BAVA are integrated on the same substrate and the desired refractive indexes of lenses are realized by a combination of a set of air-filled holes in the substrate. Prototypes of the modified BAVA with lenses (BAVA-Ls) are designed, fabricated, and experimentally investigated as well. Measured results show close agreement with simulation. The proposed BAVA-Ls exhibit promising performances such as smaller ripple levels in E-plane mainlobe, wider H-plane beamwidth, higher aperture efficiency, and excellent group delay, while maintaining good bandwidth characteristics over 2 to 18 GHz.
关键词： effective medium theory,dielectric lens,ultra-wideband (UWB),Balanced antipodal Vivaldi antenna (BAVA)
更新于2025-09-23 15:21:01
-
An antipodal Vivaldi antenna for improved far-field properties and polarization manipulation of broadband terahertz quantum cascade lasers
摘要： We present an antipodal Vivaldi antenna for broadband double metal waveguide terahertz quantum cascade lasers and frequency combs. Its exponentially curved flare profile results in an adiabatic in-plane mode expansion, producing an improved far-field with a single-lobed beam of (23° × 19°) full width half maximum with an octave-spanning bandwidth. The antenna also acts as a wave retarder, rotating the polarization from vertical toward horizontal polarization by a frequency-dependent angle. The laser’s emission spectrum and current–voltage characteristics are not affected, as well as frequency comb operation. Measurements agree well with numerical simulations, and the proposed antenna covers a broad spectral range (1.5–4.5 THz).
关键词： antipodal Vivaldi antenna,broadband,polarization manipulation,far-field properties,terahertz quantum cascade lasers
更新于2025-09-23 15:19:57
-
[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Modified Antipodal Vivaldi Antenna with Elliptical and Sinusoidal-Shaped Loads
摘要： This paper proposes a novel method of designing an ultra-wideband Antipodal Vivaldi Antenna with Elliptical and Sinusoidal-shaped Loads. The modified antenna shows better at low cut-off frequency in terms of return loss and gain throughout a bandwidth from 800MHz to 20GHz with good performance.
关键词： Antipodal Vivaldi Antenna (AVA),Ultra wideband (UWB),loaded
更新于2025-09-19 17:15:36
-
[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) - Design of a Compact Wideband Dual-Polarization Antipodal Vivaldi Antenna Array
摘要： A compact wideband dual-polarization antipodal Vivaldi antenna is proposed in this paper. This proposed antenna mainly consists of two orthogonal antipodal Vivaldi antennas and one cross-shaped metal block. Each of the antipodal Vivaldi antennas with three layers of metal is etched on the two layers of substrates with a size of 38×42×1.5 mm3. Moreover, the cross-shaped metal block with a height of 44 mm is mounted on the corner of the reflection ground plane in each periodic cell, which can fix these antennas enabling of guaranteeing the robustness of this proposed antenna. Obviously, compared to the traditional Vivaldi antenna, this proposed antenna is convenient to replace some elements if necessary. In additional, the simulated imped- ance bandwidth (active VSWR≤3) for both horizontal polariza- tion antenna and vertical polarization antenna is about 94.5%, ranging 1.2 GHz to 3.35 GHz, while the main beam is scanning from -45o to 45o in azimuth plane and from -30o to 30o in eleva- tion plane. The detailed simulated results and analysis of the proposed conformal antenna array will be presented.
关键词： Wideband antenna,Dual-polarization,Antipodal Vivaldi antenna
更新于2025-09-10 09:29:36
-
Performance enhancement of novel antipodal Vivaldi antenna with irregular spacing distance slots and modified-w-shaped metamaterial loading
摘要： This paper proposes a novel enhanced far-field performance antipodal Vivaldi antenna (AVA) by including slots into the flare with irregular spacing distance between each other and modified-w-shaped metamaterial (MWSM) unit cells etched on both sides of the substrate. The MWSM unit cell is simulated in finite element method commercially available software HFSS version16 and the effective parameters of the meta-atom are extracted by homogenization retrieval method based on transmission and reflection coefficients. Electric field and surface current distribution are displayed to qualitatively explain the occurrence of near-zero index permittivity, permeability and refraction index in 10 GHz. The unloaded and loaded modeled AVA simulation is provided, respectively, in detail and manufacturing procedure is conducted to verify the effectiveness of the suggested ideas. The return loss measurement indicated a good impedance match between the bare AVA and the loading composite MWSM unit cells despite little discrepancy compared to the simulation results. Numerical simulation reveals that the gain of the composite AVA increases from 7.5 to 11.52 dB after loading with the irregular spacing distance slots in the flare and MWSM unit cells etched substrate. The half-power beamwidth decreased from 72.4° to 41.4° for the E-plane and reduced to 33.38° from 63.4° for the H-plane, respectively. The measured results of the fabricated prototype are consistent with the simulated ones with slight discrepancy. This presented strategy will combine the advantages of the lens effect of metamaterial on the AVA and modified radiating flare, thus keeping the low profile of the whole structure all the time.
关键词： performance enhancement,modified-w-shaped metamaterial,Antipodal Vivaldi antenna,irregular spacing distance slots
更新于2025-09-09 09:28:46
-
IMPROVEMENT OF RADIATION CHARACTERISTICS OF BALANCED ANTIPODAL VIVALDI ANTENNA USING TRASFORMATION OPTICS
摘要： Transformation optics is a convenient method to control paths of electromagnetic waves and radiation characteristics of antennas. In this paper, we try to increase the gain of Balanced Antipodal Vivaldi Antenna (BAVA) over 8{16 GHz frequency band using an optical conformal transformation. The proposed antenna can be implemented by ordinary dielectric materials and graded photonic crystals (GPCs). In this designed BAVA, better side-lobe level (SLL) and cross-polarization are achieved compared to a conventional BAVA. Simulation results validate the performance of the design approach.
关键词： graded photonic crystals,Transformation optics,Balanced Antipodal Vivaldi Antenna,cross-polarization,side-lobe level,gain improvement
更新于2025-09-04 15:30:14