Ultra compact quad band resonator based on novel D-CRLH configuration

This paper represents an ultra-compact quad band resonator based on novel configuration of dual-composite right/left handed transmission line. This design broaches quad band for 7.3 GHz, 8.3 GHz, 11.9 GHz, and 13.8 GHz along with insertion losses of 2.2 dB, 0.27 dB, 2 dB, and 1.5 dB, respectively. Furthermore, the return losses are 12.2 dB, 36 dB, 20.5 dB, and 19.5 dB, respectively. The quality factor proclaims selectivity equals 42.33, 15.58, 15.87, and 31.1, at the four frequencies respectively. The paper amplifies the equivalent circuit design, mathematical study, and 3D full-wave simulation. Additionally, the design actualizes a compactness size of 13.2 × 16.5 mm
²
(0.548 × 0.6855 λ
g
²
).