In this paper, design of Substrate Integrated Waveguide (SIW) broadband unequal power divider is presented. A simple design technique to implement the unequal power division while maintaining a broad bandwidth is achieved only by changing the length of the step in the coupling region and H-plane matching step at the input while keeping all other dimensions same. A set of design curves are also presented to extend the proposed design technique to a large range of unequal power division. Two fabricated prototype of 1:4 and 1:8 power divider are presented which operate throughout the X band (8-12 GHz). © 2015 IEEE.