Multiband L-Shaped Slot Antenna Loaded with Split Ring Resonator

A multiple band SRR loaded L-shaped slot antenna (LSA) is proposed. It is demonstrated that an off-centered microstrip-fed slot antenna shows dual resonant bands with similar radiation patterns at 2.34 GHz for WiFi applications and 2.80 GHz-3.95GHz for WiMAX applications. When a compact split-ring resonator (SRR) is placed close to the feeding microstrip, it produces a new resonant mode which merges with the second higher resonant mode of the antenna at 3.47 GHz. Thus a wider bandwidth can be obtained with a -10 dB bandwidth fraction around 10.7% and 33.14%, while the corresponding realized peak gains and radiation efficiencies are 3.64 dBi (79.55%) and 5.21 dBi (79.11%), respectively. The dips in S(1, 1) are obtained for 2.34 GHz, 2.85 GHz and 3.47 GHz. The radiator has a total size of 160 x 120 x 1.6 mm(3) or 1.25 lambda x 0.94 lambda x 0.012 lambda at 2.34 GHz.