Dual-Band Negative Permittivity Metamaterial Based on Cross Circular Loop Resonator With Shorting Stubs

In this letter, a novel design of dual-band negative permittivity metamaterial is presented, which is based on a cross circular loop resonator (CCLR) with shorting stubs. The electromagnetic characteristics of this metamaterial are analyzed straightforwardly by an equivalent circuit. Numerical simulations and microwave experiments are further employed to illustrate the theoretical expectations. Moreover, the dependence between both the two frequencies and the positions of shorting stubs are discussed. Our results open a way to design the dual-notched ultrawideband (UWB) antennas and filters and dual-band metamaterial absorbers.