Design comparison of square and circular dual band microstrip antenna

This paper describes the design of the dual band microstrip antenna using scaling factor technique and inset feed. Square and circular shaped patches have been used to investigate any improvements that can be achieved. The antennas were designed to operate in the ISM band at 2.4 GHz and lower UNII band at 5.2 GHz. The dimensions of each single element of the microstrip antenna, at these operating frequencies were calculated using transmission line model. Two elements of inset fed antenna were used for each frequency band. The simulation process was done using the Agilent Advanced Design System. The scaling factor of 1.05 has been chosen for the design starting from the lowest resonating frequency at each band. The antennas have been fabricated on FR4 microstrip board with epsiv_r = 4.7 and tan delta = 0.019 using the wet etching technique and proved to be operating with adequate bandwidth and radiation characteristics.