Abstract: The double frequency flat parabolic surface antenna for spaceborne radar was designed, which comprised of twocoplanar L waveband reflecting surface antenna and C waveband reflecting surface antenna. The bottom layer film printed copperfilm, which is the metal ground plane of L waveband flat parabolic surface antenna. The middle layer film printed L waveband flatparabolic surface antenna element, which is also the metal ground plane of C waveband flat parabolic surface antenna. The top layerprinted C waveband flat parabolic surface antenna element. As flat parabolic surface antenna has little weight and prices, it will bewidely applied in military and civil application field.