A wideband curved slots antenna established on a substrate integrated waveguide (SIW) technology is presented in this paper for radar and satellite applications. The structure of the proposed antenna is consisting of a microstrip antenna with two curved slots etched on the top of radiation plane and located one on top of the other for bandwidth enhancement. This antenna has been printed on substrate from an FR-4 with εr = 4.3 of and thickness of 1.6 mm. The optimized antenna resonate frequencies are 11.34 GHz and 18.42 GHz with a fractional bandwidth of 500 MHz about (4.409 %) and 4.473 GHz about (24.29 %), respectively. The achieved peak gain is about 6.82 dB and 3.9 dB over the operating frequencies, respectively, this makes it suitable for radar and satellite applications with good matching and return loss characteristics. The design model and performance evaluation of a proposed antenna has been executed by EM simulator, CST Microwave Studio