On-line RF built-in self-test using noise injection and transmitter signal modulation by phase shifter

For on-chip self-test of radar ICs, loopback test using a signal feedback path from transmitter to receiver is state-of-the-art. Usually, such a loopback test is performed periodically after a number of application-mode chirps. The traditional loopback test has two drawbacks: it is performed intermittent to the application mode, not within the application mode. Moreover, it cannot detect the case that the attenuation from transmitter to receiver becomes too low due to defects on the IC, or due to targets very near to the antennas. This paper proposes an advanced loopback test not intermittent to the application, but during application mode. That way, spurious defects like transient faults (also known as Single Event Upsets) can be detected; moreover, an error-prone plausibility check of the received signal is avoided. To detect receiver saturation due to near targets, modulating the transmitter output signal using a phase shifter is proposed.