An integrated 77-GHz six-port receiver front-end for angle-of-arrival detection

In this publication an integrated six-port receiver front-end for angle-of-arrival detection of 77-GHz signals is presented. Applications of the circuit are direction finding, auto-motive radar calibration, or high precision industrial radar. The measurement principle is based on superposition of two incident signals and power detection. The circuit has two input amplifiers, a broadband passive six-port network, and four power detectors. The integrated circuit has a power consumption of 95mW with 5V supply voltage. It is fabricated in a 200-GHz f_T SiGe bipolar technology and occupies only 1028 × 1128 μm². Functionality is demonstrated by applying two different frequencies at the input ports. A simple calibration method is proposed and all calibration parameters are calculated.