Bandwidth enhancement of compact and wideband square microstrip patch antenna for WLAN/WiMAX applications in C-band

This paper presents a compact and wideband square microstrip patch antenna using low cost and easy available FR-4 substrate of ground size 30 mm x 30 mm (0.51 x 0.51 lambda(2)(0) at lowest resonant frequency 5.07 GHz). The radiating patch of antenna is designed by embedding three T-shape notches of same dimension formed by two rectangular notches of size 6 mm x 5 mm and 3 mm x 2 mm. The radiating patch is optimized by parametric variation of notches and feed line. The wideband fractional bandwidth (S-11 < -10 dB) of 47.2% (2810 MHz) is achieved from 4.55 to 7.36 GHz with good return loss of -47.27 dB at 5.07 GHz for an optimized dimension of notches and feed line. However, the measured fractional bandwidth of 43.9% (2340 MHz) is achieved from 4.16 to 6.50 GHz with return loss of -37.34 dB at 5.14 GHz. A stable simulated gain of 4.69 to 5.93 dBi and measured gain of 4.4 to 5.9 dBi is observed in complete resonating band. The antenna is excited by line feed of 50 Omega and simulated by IE3D simulation tool. The entire resonating band 4.55-7.36 GHz is suitable for different applications in C-band (4-8 GHz).