Metamaterial inspired multi-split square shaped printed antenna for WLAN applications

This paper describes the design of a compact dual band microstrip antenna based on metamaterial inspired split ring radiating element and a complementary spilt ring resonator (CSRR). The antenna has a very compact dimension of 20×20×0.8 mm3. It covers the 2.5/5.2/5.8 GHz frequencies, pertaining to IEEE 802.11 b/g/a standards suitable for WLAN applications with a -10dB impedance bandwidth of 250 MHz and 860 MHz. The CSRR creates a negative permittivity region, thus providing miniaturization of the antenna and the introduction of additional split gaps in the radiating element creates a positive permeability within the desirable frequency range, yielding better impedance matching. The negative properties of those structures are verified using S-parameter retrieval method. A prototype of the proposed antenna is fabricated and the measured results are fairly in good agreement with the simulation results. Dipole like radiation patterns are observed at both the operating frequencies. The measured peak gains are 0.58 dBi, 1.27 dBi and 2.10 dBi at 2.5, 5.2 and 5.8 GHz respectively.