Digital phase correction for multiplexed ADCs in low-cost Six-Port interferometers

Six-Port based radar systems are often addressing the low-cost metrology market. Currently, the analog-to-digital converter (ADC) is one of the most expensive components as it needs to simultaneously sample the four baseband signals of the Six-Port interferometer. This paper studies the feasibility of digital phase correction techniques to achieve simultaneous sampling with only a single multiplexed ADC in low-cost Six-Port systems. A system demonstrator featuring a low-power 16 bit micro-controller will be shown which compensates the conversion error due to the multiplexing delay with an efficient polyphase implementation leading to a measurement update rate of 2000 distance values per second.