Six-Port based direction finding and ranging

The Six-Port concept is known since decades as a precise device for complex valued signal handling. It has shown its functionality for metrology applications as well as for broadband I/Q data reception. Due to its extraordinary phase resolution and low cost implementation two specific industrial applications get more and more into focus: Six-Port based distance measurements and direction finding. In this paper a review on this promising concept will be given for both, ranging and angle of incident detection featuring sub-millimeter range resolution and measurement value update rates in the two digit kilohertz range. Furthermore, similarities and differences of Six-Port technology with common radar concepts will be discussed.