Testing RF circuits with true non-intrusive built-in sensors

We present a set of sensors that enable a built-in test in RF circuits. The key characteristic of these sensors is that they are non-intrusive, that is, they are not electrically connected to the RF circuit, and, thereby, they do not degrade its performances. In particular, the presence of spot defects is detected by a temperature sensor, whereas the performances of the RF circuit in the presence of process variations are implicitly predicted by process sensors, namely dummy circuits and process control monitors. We discuss the principle of operation of these sensors, their design, as well as the test strategy that we have implemented. The idea is demonstrated on an RF low noise amplifier using post-layout simulations.