DESIGN OF A SIMPLE MULTI-BAND ANTENNA WITH A PARASITIC C-SHAPED STRIP

A new design of multi-frequency antenna is presented. The antenna comprises a direct-radiating patch and a parasitic C-shaped strip, which generate resonant modes to cover 2.4/3.6/5.2/5.8 GHz bands. The design was experimentally verified by constructing the antenna on a PTFE (epsilon(r) = 2.4) dielectric substrate (30 mm * 36 mm * 1 mm) and exhibiting its impedance bandwidth and radiation characteristics at the three bands. The measured vertical bar S11 vertical bar < -10 dB (VSWR < 2 : 1) bandwidth in the 2.4 GHz band is 550 MHz ((2.3-2.536 GHz), and it covers the bandwidth required for 2.4 GHz WLAN. The 5.2/5.8 GHz resonant mode has a bandwidth of 1.44 GHz (4.67-6.11 GHz) covering 5.2/5.8 GHz WLAN bands. The obtained impedance bandwidth reaches 790 MHz (spans from 3.15 GHz to 3.94 GHz). A rigorous experimental evaluation confirms that the proposed antenna maintains good radiation. Detailed design steps and experimental results for the designs are studied and investigated in this paper.