A rhombic ring monopole antenna with stripline and ring resonator for multiband operation

This paper presented a rhombic ring monopole antenna with stripline and ring resonator for multiband operation. The antenna is created by adding a stripline in a rhombic ring radiator and placing a ring resonator on the bottom layer of the radiator. It can support the multiple resonant frequencies for wireless communication systems. The antenna dimension is about 36 × 48 mm². The results confirm the good agreement between simulation and measurement. The antenna operates with |S11| level <; -10 dB on impedance bandwidths of 16.11%, 9.8%, and 37.43% at the resonant frequencies of 1.8 GHz, 2.45 GHz, and 3.5 GHz, respectively covering the application bands of LTE 1800, WLAN IEEE802.11b/g, WiMAX and IMT Advance Systems. The radiation patterns are omni-directional at all of operating frequencies and the average gain of the antenna is about 2.4 dBi.