Compact Dual-Band CPW-Fed Zeroth-Order Resonant Monopole Antennas

A compact dual-band coplanar waveguide (CPW)-fed monopole antenna loaded with a split-ring resonator is presented in this letter. The split-ring resonator is shunt-connected to the folded monopole and has generated a shunt capacitance or inductance as an electrically small resonator yielding a zeroth-order resonant monopole. The proposed antenna has a length of 0.062 wavelengths and a width of 0.06 wavelengths and exhibited -10-dB impedance bandwidths of 50 MHz at 1780 MHz and 1120 MHz at 3440 MHz. The radiation patterns show a dipole-like mode at 1710 MHz and a monopole-like one at 3820 MHz. The measured radiation efficiencies are measured as 17% at 1710 MHz and 88% at 3820 MHz.