In this paper, a compact electronically beam switchable leaky-wave antenna (LWA) based on TE20 mode substrate integrated waveguide (SIW) is proposed at X-band. The microstrip power divider-slotline transitions are utilized to excite TE20 mode SIW array in order to enhance the overall radiation capability of the designed structure. The tilted rectangular radiating slots with triangular amplitude variation are etched out on the top of SIW resulting in large bandwidth and low cross-polar level. Further, the single complementary split-ring resonator (CSRR) is placed on the bottom plane with four diodes. Depending on the biasing states of the diodes, the radiated fan beam is switched four different directions. The proposed antenna is working within the frequency range of 9 - 11.7 GHz (S11<-10dB) having the beam scanning range of 75o with a maximum gain of 14 dBi. © 2019 IEEE.