We propose and investigate a methodology based on convolved electric and magnetic currents for the generation of multi-band responses over a space-shared radiating surface.First,a single wideband antenna operation pri...We propose and investigate a methodology based on convolved electric and magnetic currents for the generation of multi-band responses over a space-shared radiating surface.First,a single wideband antenna operation principle based on inter-leaved dipole and slot modes is studied and analyzed using full-wave simulations followed by a qualitative time domain analysis.Subsequently,a 2×2 dual-band radiating unit is conceived and developed by closely arranging single wideband antennas.In this case,multimode resonances are generated in a lower frequency band by a proper convolving and coupling of the magnetic and electric currents realized in the gaps between the antennas and on the surface of the antennas,respectively.This methodology can be deployed repeatedly to build up a self-scalable topology by reusing the electromagnetically(EM)connected radiating surfaces and gaps be-tween the radiating units.Due to the efficient reuse of the electromagnetic region for the development of multiband radiation,a high aperture-reuse efficiency is achieved.Finally,as a proof of concept,a 2×4 dual-band array operating in Ku-and Ka-bands is devel-oped and fabricated by a linear arrangement of the two developed radiating units.Our measurement results show that the proposed antenna array provides impedance and gain bandwidths of 30%and 25.4%in the Ku-band and 10.65%and 8.52%in the Ka-band,respectively.展开更多
To reduce the cost and achieve high diffraction efficiency, a modified moir@ technique for fabricating a large- aperture multi-level Fresnel membrane optic by a novel design of alignment marks is proposed. The modifie...To reduce the cost and achieve high diffraction efficiency, a modified moir@ technique for fabricating a large- aperture multi-level Fresnel membrane optic by a novel design of alignment marks is proposed. The modified moire fringes vary more sensitively with the actual misalignment. Hence, the alignment accuracy is significantly improved. Using the proposed method, a 20 μm thick, four-level Fresnel diffractive polyimide membrane optic with a 200 mm diameter is made, which exhibits over 62% diffraction efficiency into the ＋1 order, and an efficiency root mean square of 0.051.展开更多
This paper presents a review of transmitarray(TA)and reflectarray(RA)antennas based on the magnetoelectric(ME)dipole antenna struc-ture.First,the basic operating principles of ME dipole,TA and RA antennas are introduc...This paper presents a review of transmitarray(TA)and reflectarray(RA)antennas based on the magnetoelectric(ME)dipole antenna struc-ture.First,the basic operating principles of ME dipole,TA and RA antennas are introduced.Next,ME-dipole-based TA and RA designs are discussed,with four antenna designs presented in detail,including two fixed-beam TA designs with high aperture efficiencies and two reconfigurable designs with a beam-scanning capability.The techniques involved in these designs are also analyzed to provide insight into the ME-dipole-based TA and RA designs.The simulated and measured results of the reported prototypes show that the introduction of the ME dipole antenna significantly broadens the band-widths of the TA and RA antennas not only in the fixed-beam designs but also in the reconfigurable designs.The ME-dipole-based TA and RA designs reported in this paper are compared to highlight their benefits and limitations.Future possible research directions and challenges are also discussed.展开更多
A low sidelobe aperture design method of multi-step amplitude quantization with pedestal is proposed, and general analysis and formulas are described. The computation results compared with our previous method "Mu...A low sidelobe aperture design method of multi-step amplitude quantization with pedestal is proposed, and general analysis and formulas are described. The computation results compared with our previous method "Multi-Step Amplitude Quantization(MSAQ)" on peak side-lobe level, aperture efficiency, normalized input power and sidelobe degradation with tolerance are given. It is shown that, under the same conditions, the method presented in this paper is better than the MSAQ.展开更多
文摘We propose and investigate a methodology based on convolved electric and magnetic currents for the generation of multi-band responses over a space-shared radiating surface.First,a single wideband antenna operation principle based on inter-leaved dipole and slot modes is studied and analyzed using full-wave simulations followed by a qualitative time domain analysis.Subsequently,a 2×2 dual-band radiating unit is conceived and developed by closely arranging single wideband antennas.In this case,multimode resonances are generated in a lower frequency band by a proper convolving and coupling of the magnetic and electric currents realized in the gaps between the antennas and on the surface of the antennas,respectively.This methodology can be deployed repeatedly to build up a self-scalable topology by reusing the electromagnetically(EM)connected radiating surfaces and gaps be-tween the radiating units.Due to the efficient reuse of the electromagnetic region for the development of multiband radiation,a high aperture-reuse efficiency is achieved.Finally,as a proof of concept,a 2×4 dual-band array operating in Ku-and Ka-bands is devel-oped and fabricated by a linear arrangement of the two developed radiating units.Our measurement results show that the proposed antenna array provides impedance and gain bandwidths of 30%and 25.4%in the Ku-band and 10.65%and 8.52%in the Ka-band,respectively.
基金supported by the National Natural Science Foundation of China under Grant No.11375175
文摘To reduce the cost and achieve high diffraction efficiency, a modified moir@ technique for fabricating a large- aperture multi-level Fresnel membrane optic by a novel design of alignment marks is proposed. The modified moire fringes vary more sensitively with the actual misalignment. Hence, the alignment accuracy is significantly improved. Using the proposed method, a 20 μm thick, four-level Fresnel diffractive polyimide membrane optic with a 200 mm diameter is made, which exhibits over 62% diffraction efficiency into the ＋1 order, and an efficiency root mean square of 0.051.
基金supported in part by the Research Grants Council of the Hong Kong SAR,China(Grant Nos.9043154(CityU 11211721)and 9042674(CityU 11217618))the National Natural Science Foundation of China(Grant No.61971370)the Guangdong Provincial Department of Science and Technology,China(Grant No.2020B1212030002).
文摘This paper presents a review of transmitarray(TA)and reflectarray(RA)antennas based on the magnetoelectric(ME)dipole antenna struc-ture.First,the basic operating principles of ME dipole,TA and RA antennas are introduced.Next,ME-dipole-based TA and RA designs are discussed,with four antenna designs presented in detail,including two fixed-beam TA designs with high aperture efficiencies and two reconfigurable designs with a beam-scanning capability.The techniques involved in these designs are also analyzed to provide insight into the ME-dipole-based TA and RA designs.The simulated and measured results of the reported prototypes show that the introduction of the ME dipole antenna significantly broadens the band-widths of the TA and RA antennas not only in the fixed-beam designs but also in the reconfigurable designs.The ME-dipole-based TA and RA designs reported in this paper are compared to highlight their benefits and limitations.Future possible research directions and challenges are also discussed.
文摘A low sidelobe aperture design method of multi-step amplitude quantization with pedestal is proposed, and general analysis and formulas are described. The computation results compared with our previous method "Multi-Step Amplitude Quantization(MSAQ)" on peak side-lobe level, aperture efficiency, normalized input power and sidelobe degradation with tolerance are given. It is shown that, under the same conditions, the method presented in this paper is better than the MSAQ.
