We describe a sputtering system which allows the simultaneous deposition of HTS films on both sides of wafers up to 5-inch diameter. The system consists of three deposition chambers in a row to cover a wafer on both sides simultaneously with three different films, such as a buffer layer, a HTS film and a contact layer. We present data on the performance of the system, such as temperature homogeneity at the substrate Location, the lateral distribution in film thickness and composition, and the properties of the deposited HTS films, on which we measured the critical current density, the field dependence of the surface resistance and the performance of stripline and disk resonators and filters.