Differential-Mode Power Detection for Built-In Self-Test of SiGe Automotive Radar Transceiver Front Ends

Abstract

Recently, the feasibility of differential-mode power detection for built-in self-test (BIST) in millimeter-wave SiGe transceiver front ends has been demonstrated. In this work, a system analysis of typical BIST scenarios is performed. Specifications for the input power levels as well as the accuracy of power detectors are derived from this analysis. A need for at least two different differential detector architectures is identified. Two detectors are derived from the differential power measurement concept, analyzed, and implemented in the 76-81-GHz automotive radar frequency band. They feature a low power consumption of 500 µW and, to the authors' best knowledge, the lowest published circuit areas of approximately 0.005 mm 2 while still being input matched to the differential 100 system impedance. Both these characteristics are essential to keep the overhead of the BIST minimal. With dynamic ranges of 30 dB and up to 46 dB for the two different architectures, the differential power detector concept can achieve sufficient performance for BIST applications. The robustness against process and temperature effects as well as noise is analyzed and reported for both detectors.