Super-compact left-handed resonator for filter applications

In this paper, novel super-compact left-handed (LH) resonator is presented, based on a grounded double spiral end-coupled to the host microstrip line. The overall dimensions of the resonator are lambdag/59 by lambdag/27, where lambdag denotes the guided wavelength. The proposed resonator shows lower insertion loss at resonant frequency and higher Q-factor in comparison with previously reported LH resonators. Using the proposed resonator, miniature 2nd and 3rd order filters are designed, fabricated and measured.