In this paper high gain reflectarray antenna for broadband applications is proposed. The proposed design, based on a novel hexagonal unit cell shows a large reflection phase range of 1000° with smooth linear phase slope. A center horn fed 11 x 11 reflectarray antenna with the proposed unit cell is designed for X Band (8 to 12 GHz) applications. It is simulated for different f/D (focus point to largest dimension of antenna) ratios to evaluate its effect. For optimum results, only two f/D ratios 1.0 and 1.96 are chosen. The simulated results show that a wide operational bandwidth of 39.6% for 3dB gain dropping is obtained over the frequency band of 8 to 12 GHz which is much improved than the previously reported results. Simulations for the f/D ratio of 1.96 shows improvement in the aperture efficiency with 3 dB gain bandwidth of 29%. This single layer, low profile reflectarray antenna can be a useful candidate for high gain broadband applications.