There has been a great deal of interest in periodic dielectric structures that exhibit photonic band gaps. Periodicity in dielectric constant results in a range of frequencies within which transmission is forbidden, known as Photonic Band Caps (PEG). PBG structures can be used as tunable filters whose bandwidth can be varied depending on the periodicity, dielectric constant etc. It is possible to construct PBG structures with one-dimensional periodicity. In this paper, we report the experimental observation of the band gaps between 10 and 20 GHz for a structure made of lossy glass slabs (ε′r = 6.1, ε″r = 0.06). This paper also presents the results on the numerical computation using transfer matrix method for the above structure for comparison. The nature of the band gaps is also investigated with respect to the spacing between the dielectric slabs and dielectric constant.