Tunable Properties Of Electronically Controlled Fishscale Metamaterials

Metamaterials have peculiar electromagnetic properties that conventional materials do not have,and have received widely attention since their appearance.However,when the shape and size of the unit structure are fixed,the electromagnetic response of the metamaterials is fixed.In order to solve this problem,active elements have been added to the unit structure to realize tunable metamaterials,and many excellent scientific research achievements have been made.Electromagnetically induced transparency(ETI)has great application value in the fields of slow light,optical signal processing,quantum switching etc.,but the conditions for electromagnetically induced transparency in atomic systems are harsh,and metamateials can achieve electromagnetic induced transparency without being limited by conditions.The simulated electromagnetically induced transparency also has characteristics such as high transparency and strong dispersion.The main research content of the thesis is tunable properties of electronically fishscale metamaterials.Several different metamaterials are designed.The tunable metamaterials are realized by PIN diodes.The electromagnetic responses of these structures are discussed systematically by theoretical simulation and experiment.The main work is as follows:We proposed a fishscale metamaterial with two horizontal lines.The EIT can be completed by changing angles of the incident wave.Then PIN diodes were embedded in the structure,the EIT phenomenon in the transmission curve was realized by two simulation methods:field circuit combination and RLC equivalent circuit.The transmission amplitude reached about 0.8.And when the current increased to 5mA,the incident angle was changed,electromagnetically induced transparency depending on the change of the incident angle was realized.Using the surface current distribution diagram at the resonance,the mechanism of EIT was explained.Finally,the above structures were experimentally verified in the microwave anechoic chamber.The experimental results were basically consistent with the simulation results.The fishscale metamaterials with different gaps are studied.We changed the position of the gaps.The transmission curve of the metamaterial shown a distinct transparent window.The addition of longitudinal metal lines to the structure also achieved tunable electromagnetically induced transparency,and we found that this electromagnetic response was insensitive to the incident angle.Finally,the tunability of the electronically controlled fishscale metamaterial was systematically analyzed.In the simulation,the current of the diode was used to control the "off" to "on" at frequency of 2.8GHz in the transmission curve.We also studied the effect of the incident angle on the transmission and found that the resonances were not sensitive to the incident angle.Resonance at the frequency of 2.8GHz was also insensitive to the diode position.But as the position of the diode moved,the resonances at frequencies of 9.8GHz and 10.8GHz appeared to overlap and separate.The experimental results were basically consistent with the simulation results.Tunable metamaterials are of great significance for many fields such as optical switching,optical sensing,and optical storage.