Some properties of digital correlation based of the fractional Fourier transform are analyzed. We generalize the architecture of a VanderLugt correlator to achieve the VanderLugt fractional Fourier transform correlator such that fractional correlation can be obtained. In this situation the Fourier transform in the classical VanderLugt is replaced by the fractional Fourier transform, and four different VanderLugt fractional architectures can be implemented. The performances of such a correlator are analyzed according to the standard criteria of signal-to-noise ratio, correlation sharpness, peak-to-correlation energy, and Horner efficiency. Here the binary image of a character is used for the test.