High sensitivity detector with robust PVT performance for 60GHz BiST phased array systems in 90nm CMOS

A built in self test (BiST) system for a 60GHz phased array chip with high sensitivity large dynamic range detectors is presented. The system measures the array phase shifter relative step with an accuracy of 5deg and the gain of the TX and RX chain through loopback with an accuracy of +/-1dB across process, temperature, and voltage (PVT). The system is composed of an RF combining detector path between chains with switched coupling, low noise detectors based on self mixing, and bias circuits that compensate for temperature and process variation. The Detector off state load on the PA output is 0.2dB.