Two types of dual periodic circuits are introduced. The distributions of passbands and stopbands are generated from their dispersion relationships. Based on the study, Brillouin diagrams of three representative specia...Two types of dual periodic circuits are introduced. The distributions of passbands and stopbands are generated from their dispersion relationships. Based on the study, Brillouin diagrams of three representative special cases are drawn; S parameters of these three cases are simulated by Aglient ADS; the S parameters of one of the three cases are verified by an experiment. The phase characteristics are compared with those generated from the dispersion relationship. The theoretical analysis and the experimental verification show that both types of the periodic structures can behave as electromagnetic band gap （EBG） structures, right-handed structures （RHS）, and left-handed structures （LHS）, when they operate at different frequency ranges. Thus, the possibility of a physical structure showing these three different characteristics at different frequency ranges is proven.展开更多
Two kinds of compact electromagnetic band gap （EBG） structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Becaus...Two kinds of compact electromagnetic band gap （EBG） structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Because of its significantly enlarged equivalent inductor and capacitance, the period of the lattice is approximately 4.5% of the free space wavelength. By insetting several narrow slits in the ground plane, the bandwidth of the main bandgap is enhanced by nearly 19%. Further effort has been made for designing a three layer compact EBG structure. Simulation results show that its period is reduced by about 26% compared to that of proposed two layer EBG structure, and the bandwidth of the main bandgap is about 3 times as that of the proposed two layer EBG structure. The detailed designs including a two layer compact 3×7 EBG array with and without defect ground plane and the three layer EBG array are given and simulation results are presented.展开更多
Six circularly polarized patch antennas with electromagnetic band gap（EBG）arranged at different locations were studied.These EBG antennas were compared in terms of impedance bandwidth,axial ratio（AR）bandwidth and ...Six circularly polarized patch antennas with electromagnetic band gap（EBG）arranged at different locations were studied.These EBG antennas were compared in terms of impedance bandwidth,axial ratio（AR）bandwidth and radiation patterns.When the EBG cells were placed closer to the edge of the substrate,the EBG antenna had a larger front radiation and a narrower bandwidth.Integrating the EBG cells closer to the center of the patch resulted in a wider impedance bandwidth,a wider axial ratio bandwidth and a decreased front gain.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 60471018)
文摘Two types of dual periodic circuits are introduced. The distributions of passbands and stopbands are generated from their dispersion relationships. Based on the study, Brillouin diagrams of three representative special cases are drawn; S parameters of these three cases are simulated by Aglient ADS; the S parameters of one of the three cases are verified by an experiment. The phase characteristics are compared with those generated from the dispersion relationship. The theoretical analysis and the experimental verification show that both types of the periodic structures can behave as electromagnetic band gap （EBG） structures, right-handed structures （RHS）, and left-handed structures （LHS）, when they operate at different frequency ranges. Thus, the possibility of a physical structure showing these three different characteristics at different frequency ranges is proven.
基金supported by the National Natural Science Foundation of China under Grant No. 60588502
文摘Two kinds of compact electromagnetic band gap （EBG） structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Because of its significantly enlarged equivalent inductor and capacitance, the period of the lattice is approximately 4.5% of the free space wavelength. By insetting several narrow slits in the ground plane, the bandwidth of the main bandgap is enhanced by nearly 19%. Further effort has been made for designing a three layer compact EBG structure. Simulation results show that its period is reduced by about 26% compared to that of proposed two layer EBG structure, and the bandwidth of the main bandgap is about 3 times as that of the proposed two layer EBG structure. The detailed designs including a two layer compact 3×7 EBG array with and without defect ground plane and the three layer EBG array are given and simulation results are presented.
基金Supported by the National Natural Science Foundation of China(61102022)the Fundamental Research Foundation of Beijing Institute of Technology of China(20120542014)
文摘Six circularly polarized patch antennas with electromagnetic band gap（EBG）arranged at different locations were studied.These EBG antennas were compared in terms of impedance bandwidth,axial ratio（AR）bandwidth and radiation patterns.When the EBG cells were placed closer to the edge of the substrate,the EBG antenna had a larger front radiation and a narrower bandwidth.Integrating the EBG cells closer to the center of the patch resulted in a wider impedance bandwidth,a wider axial ratio bandwidth and a decreased front gain.
