Millimeter-wave application in intelligent vehicle sensor and others has been in great demand recently for it's small size, high data rate and high resolution property. In this paper, we report our design of a 35 GHz finline balanced mixer. Suspended Substrate Stripline (SSS) bandpass filter was designed for high rejection and high security performance. Independent components were designed and simulated using Ansoft HFSS and the simulated results were agreeable with the measured results.