基于电阻型频率选择表面的超宽带紧耦合阵列

Ultra-wideband tightly coupled array with resistive frequency selective surface

针对接地板严重影响紧耦合天线阵列(Tightly Coupled Array,TCA)阻抗带宽的问题,设计了一种基于电阻型频率选择表面(Resistive Frequency Selective Surface,RFSS)的多层结构超宽带TCA,分析了电阻膜方阻及单元间耦合对阻抗带宽的影响,并对其扫描及未扫描时的性能进行了仿真分析.结果表明:通过在天线阵列与接地板之间加载开口谐振环结构的RFSS,可减小接地板反射,抑制天线短路点,显著增加其阻抗带宽,其辐射性能在整个带宽内均较稳定;由于RFSS加入了损耗,天线阵列增益有所降低.该多层结构TCA具有带宽宽、体积小、易共形等特点,在超宽带小型化相控阵天线中有良好应用前景.

In order to solve the problem that impedance bandwidth of tightly coupled array（TCA）was greatly affected by ground plane, a multilayer TCA was de signed with a resistive frequency selective surface（RFSS）,the influence of sheet resistivity and mutual coupling to impedance bandwidth was analyzed, the performance of TCA with and without scaning was simulated. Results indicate that impedance bandwidth of this TCA is greatly improved by inserting a split ring resonator RFSS between array and ground plane, which minishes ground plane reflection and suppresses short circuited frequency. The radiation performance is stable during whole impedance bandwidth and the gain of this TCA is decreased due to the loss of RFSS. This multilayer TCA has characteristic of broad bandwidth, low profile and easily conformal installation, which can be applied to small ultra-wideband phased antenna array system.