In this paper, we have proposed a mathematical model for the design of a hybrid beam-forming antenna. Antenna beam is steered by the hybrid of switched parasitic array and phased array approach, this technique is based on our recently awarded patent. Our design consists of two circular arrays of parasitic elements, each array has six parasitic / passive elements around an active element. Phased shift between the excitation currents is introduced by adding a phase shifter. Antenna beam is steered by the switching (opening / shorting) of the parasitic elements as well as by regulating phase shift. In conventional switched parasitic array antennas beam-steering is not continuous. However, by using our approach continuous beam-steering (0°-360°) is achieved in the azimuth plane. Moreover our antenna gain is 4 dB higher than the conventional switched parasitic array and electronically steerable parasitic array radiator (ESPAR) antennas, typical gain of such antennas is 6.5 dBi.