Compact quad-band superconducting metamaterial filter based on split ring resonator

In this Letter, a multi-resonant split ring resonator (SRR) is proposed for multi-band application. Its equivalent circuit model and even/odd-mode analysis are investigated. To verify this design methodology, a quad-band high-temperature superconducting (HTS) metamaterial structure is designed and fabricated with a compact size of 11.1 mm x 14.95 mm (about 0.149 lambda(g) by 0.2 lambda(g)). The insertion losses at each passband are 0.13, 0.07, 0.135, and 0.2 dB, respectively. The temperature effects and power handling capability of the quad-band HTS filter are also studied and the results show that the device has both perfect quad-band bandpass performance (temperature < 77 K) and perfect bandstop performance (temperature > 100 K) for the multi-band communication and superconductor switch applications. (C) 2014 AIP Publishing LLC.