The aim of this paper is to design the effective shape of a microstrip patch antenna which can provide lower return losses, better gain and performance for X-band (2 GHz to12 GHz), Ku-band (12 GHz to 18 GHz) and K-band (18 GHz to 26 GHz) applications. Attempts have been made to optimize the antenna performance by increasing the number of slots, by using slots in different position in patch and by using array technique. The simulation is performed by using GEMS simulator which is commercially available antenna simulator. The antenna is designed by using Taconic TLY-5 dielectric substrate with permittivity □r =2.2 and height, h=1.588 mm. Without using array technique we have got the return losses in the range of -20 db to -25 db at the frequencies around 19.5 GHz. The series feed array offers -7.25 db return loss around 11.5 GHz, -17.5 db return loss around 16 GHz and -13db return loss around 21GHz. Therefore, this antenna is suitable for X-band, Ku-band and K- band applications.