Non-invasive monitoring of CMOS power amplifiers operating at RF and mmW Frequencies using an on-chip thermal sensor

In this paper a non-invasive, contact-less technique for the on-chip observation of PA operation is presented. It uses a differential temperature sensor that transduces the temperature increase due to the power dissipated by active transistors operating at high frequencies into a low frequency signal that is proportional to some relevant PA figures of merit, such as output power or PAE. The technique is demonstrated by using the same thermal sensor in two different PAs (a 2 GHz PA and a 60 GHz PA) implemented with a 65nm CMOS process.