A frequency translator according to the serrodyne principle, for simulating Doppler shifts within 0-400 Hz, is designed, built, and verified. It is based on commercial analog controlled phase shifters. Serrodyne design aspects as well as control signal hardware and software are described. The design is implemented in a multipath propagation simulator for over-the-air tests of car communication. Measurements on the complete multipath propagation simulator verify the performance of the presented frequency translators.