一种双频能量选择表面的设计

文中提出了一种能在两个工作频段对高功率微波进行自适应防护的双频能量选择表面,它由两个分别加载了二极管和集总电容的开口谐振环构成,在C 波段(5. 4~6. 0 GHz)和S 波段(2. 6~2. 8 GHz)各产生一个信号通带。当入射波的场强超过设定阈值时,二极管被谐振环上的感应电压导通,使得谐振环的谐振状态发生变化,两个信号通带自动关闭,从而屏蔽高功率微波。通过表面电流和电场分布阐述了设计思路和工作原理。采用PCB 工艺制作了样件并分别在弱场和高功率辐照下进行了传输系数的测量实验。仿真和实验结果具有良好的一致性,表明双频能量选择表面在两个信号通带的插入损耗均小于1 dB,防护效果大于15 dB(其中C 波段的信号通带内防护效果大于25 dB),能对高功率微波进行有效防护。

Design of A Dual-band Energy Selective Surface

The Energy Selective Surfaces (ESSs) are periodic structures that loaded with nonlinear devices or materialsto obtain high power protection functions. The proposed structure is realized by periodic split resonance rings (SRR) loadedwith diodes or lumped capacitors. Specifically, there are two different SRRs in each unit and they are loaded with a diode andlumped capacitor, respectively. With a good design of the geometry parameters and lumped elements, a passband at S band(2. 6 - 2. 8 GHz) is generated by the SRR loaded with a lumped capacitor and a passband at C band (5. 5- 6 GHz) is generatedby the SRR loaded with a diode. By the coupling effects between two SRRs, the two passbands are modulated simultaneouslyby only one diode. The physical mechanism is demonstrated with the distribution of surface currents density and electric fieldand some important parameters are also discussed in detail. It proves that the transmission characteristics of the passbands aredetermined by different parameters, respectively, and they can be modulated independently. Then a prototype of the proposedstructure is fabricated and measured under low-power signals and high-power signals, respectively. The results of simulationsand experiments agree well, showing that the proposed dual-band ESS poses an insertion loss lower than 1 dB during the twooperating frequency band for low-power signals. And for high-power signals, the dual-band ESS provides more than 15 dB and25 dB shielding in the operating frequency band in S and C band, respectively. The excellent nonlinear transmission characteristicand dual operating band make the proposed ESS practical for high power microwave protection.