ABSTRACT This paper demonstrates the design and simulation analysis in association with fabrication measured results of an orbital angular momentum (OAM) substrate integrated waveguide (SIW) slot antenna working at 10 GHz in X band. Simple feeding networks including 90° hybrid couplers are introduced to excite traveling waves inside four separated circular resonators radiating eight OAM modes beams. The antenna is composed of two PCB layers where the circular resonators and feeding networks are located, respectively. The measured results including S-parameters and radiation patterns are in good agreement with the simulation results in HFSS.