This paper presents the development of the six-port baseband processing system for short range radar based sensor. Short range radar involved in many applications such as the used in the automotive system. The analog baseband circuit commercially exists nowadays, but it a little bit bulky and expensive. In this paper, the design of a RF power detector using microstrip technique is presented. The design of diode detector circuit is simulated using Keysight ADS software tool. The design of the diode detector includes the matching network, RF choke and the low pass matching. When the design of diode detector completed, the development of baseband processing system is accomplished using microcontroller board. The algorithm of obtaining Direction of Arrival (DOA) phase wave is executed using microcontroller board. The details of the theory, simulation and results are presented in this paper.
