In this paper, a new periodic Leaky-Wave Antenna (LWA) based on Substrate Integrated waveguide (SIW) technology is proposed and investigated. To scan the beam in backward as well as forward plane, a periodic leaky LWA has been employed in this work. Periodic LWA also offers the advantage of larger bandwidth with higher gain. This LWA is realized using a sensibly developed SIW technology to achieve the proposed geometry in a planar form. In this antenna, multiple square-shaped slots are etched into the top plane for radiation. An investigative study on stop-band minimization and thereby increasing scan range, scan resolution has been performed by varying the periodic range between the slots. The antenna shows a scanning from -78° to 73° in the frequency range of 7.5 to 14.8 GHz with a peak gain of 11.8 dBi. It is observed from simulation studies that the period 20 mm is the best choice with respect to the stopband, scan resolution, and gain.