A triple band compact asymmetric monopole-SRR based antenna for Wi-Max, WLAN and RFID applications

In this paper, a triple band very compact asymmetric monopole antenna with an electrically coupled split ring resonator (SRR) is presented. The operating frequencies cover the worldwide interoperability for microwave access (WiMAX), wireless local area network (WLAN), and Tagometry (Telemetry using RFID) applications. The asymmetric monopole is fed by a microstrip line, whereas the SRR is inductively coupled with the radiating element which gave triple band of resonances. The electric field-coupled SRR yields its resonance at 3.37 GHz in addition to the fundamental wideband resonances obtained by the asymmetric monopole. The simulated operating bands 3.37 GHz, 5.62 GHz, 8.26 GHz are suitable for WiMAX, WLAN and RFID Tagometry bands respectively. The proposed antenna has a very compact size of 12 × 15 × 1.6 mm3 with FR4 substrate. Very good 50 ohm impedance matching of the antenna for all three resonances by getting S11 as -38.5 dB, -39.9 dB, -30.7dB for corresponding three resonance frequencies respectively. Good impedance bandwidth achieved for third resonance 13.74% and desired radiation characteristics of antenna obtained which can use for above noted three applications. The antenna simulations and parametric studies have been done using CST Microwave Studio.