Parameters of a microstrip patch antenna such as the resonant frequency, radiation conductance, and the bandwidth are calculated. The rectangular microstrip patch antenna fed by a microstrip transmission line is fabricated and its resonant frequency, input voltage stanging ratio(vswr) and bandwidth are measured. The measured resonant frequency for 13.0mmx9.7mm copper clad woven polytetrafluoroethylene/glass laminate plat is 9.06Ghz, where the calculative is 9.00Ghz for 13.0x9.7mm plate. The measured vswr shows that the bandwidth of the antenna is 225MHz for vswr less then 2.0 which the calculated quality factor of the patch gives the bandwidth of 280GHz. The measured radiation pattern for 5 element as well as 4 element patch array shows less than 4dB deviation in the first side lobes from the designed values for both E and H plane pattern. This diviation is believed to be the power division errors of the power divider.