Research On Frequency Selection Surface Design And Reconfigurable Technology Based On Field Path Synergy

As a periodic structure,the frequency selective surface(FSS)is widely used in communications,stealth,and other fields due to its unique filtering characteristics.With the vigorous development of science and technology.In order to solve this problem,this thesis first proposes a rapid design method of field and path collaboration,starting from the equivalent circuit,and guiding the FSS structure design with the electromagnetic response of each component in the equivalent circuit.Then,this thesis proposes two reconfigurable design methods of FSS to meet more complex electromagnetic application scenarios,one is to load active devices,and the other is to use 4D printing to remember metal materials.The main research content of this thesis is divided into the following three parts.1.A prototype of the inductively coupled second-order band-pass filter circuit was established,which was converted into a non-resonant cascaded FSS structure,and the specific electromagnetic response of the FSS structural parameters was obtained through the analysis of the equivalent circuit,and finally a FSS with a passband of 5 to 6GHz was quickly designed,with a profile of only 0.022λ(λ is the passband center frequency),and the maximum overband fractional bandwidth was only 8.4%.2.The tuning differences of varactor diodes loaded at different positions in the equivalent circuit are analyzed,and the general principle of selecting varactor diodes when designing FSS is given,and based on this,two reconfigurable FSS are designed,one is band-stop-bandpass FSS,the change rate of the passband center frequency can reach 1.52,and the change rate of the stopband center frequency can reach 2.94;the other is band-pass FSS,whose passband center frequency change rate can reach 2.6.Both FSS operate in the S-and C-bands.3.The characteristics of memory metal materials used in 4D printing technology were explored,and this characteristic was applied to the design of FSS,and two types of FSS were designed,one was memory metal FSS and the other was memory metal driven FSS.The former relies on the change of the form of the memory metal itself to change the resonant frequency of FSS,and the latter uses the memory metal to drive other metal structures to change the resonant frequency.The FSS is designed to realize reconfigurable functions in the X-band.