A new 94-GHz six-port collision-avoidance radar sensor

A new 94-GHz collision avoidance radar sensor is proposed. The receiver front-end module is based on a six-port phase/frequency discriminator (SPD). The SPD, composed of four 90/spl deg/ hybrid couplers, is manufactured in a metal block of brass using a computer numerically controlled milling machine. Simulation and measurement S-parameters of the SPD are presented in the frequency band. New SPD computer models are generated and used in the system simulations. Preliminary measurements and system simulations performed to obtain the relative velocity of the target and its distance are presented. Statistical evaluations show an acceptable measurement error of this radar sensor.