Compact dual-band coplanar waveguide antenna based on composite right/left-handed quarter-wave type resonator

In this paper, a compact dual-band antenna is successfully proposed and presented. This type of antenna consists of a coplanar waveguide (CPW) composite right/left-handed (CRLH) quarter-wave type resonator, and a CPW feed network. The characteristics that the CRLH resonator can resonate at the frequency where the electrical length is phase-leading or negative, is used to design a smaller size resonator as compared with the conventional phase-delayed microstrip-line resonator. The feed network is composed of a series 50 Ω CPW transmission line and an interdigital capacitor, which can also reduce the antenna´s size further and achieve impedance matching well. The compact dual-band antenna operational frequences are n=-1 resonance mode at 4.25 GHz and n=1 resonance mode at 5.46 GHz. Simulated and measured results are observed, which show a good agreement.