Temperature-Dependent Study of Large-Signal Reliability of p-FET-Based Power Amplifier for mmWave Applications

For the first time, the temperature dependence of RF reliability of a power amplifier (PA) is investigated for the mmWave frequency band. The PA comprises a common source configured single pFET fabricated in 45RFSOI technology by GlobalFoundries. Temperature dependence of DC and large-signal figures of merit (FOMs) are analysed as a function of RF power levels and DC stress at the gate terminal for a continuous wave (CW) frequency of 26.5GHz. In this study, we have also investigated the relationship between temperature and the time slope exponent obtained from the % degradation in ON current $(I_{ON})$ for different operating regions of PA. The degradation mechanism involves trapping hot holes in pre-existing traps and the generation of new traps in the oxide due to hot holes. A non-linear relationship between DC and RF FOMs $(I_{ON}$ and $P_{OUT})$ is investigated for the increasing temperature. The non-linear relationship extracted from the slope between ${\Delta }I_{ON}$ and ${\Delta }P_{OUT}$ shows that the DC performance is impacted more than the RF performance with the increasing temperature. Degradation in output power of PA cell increases with the temperature. As a result, the lifetime of PA cell decreases with increasing temperature and fails to achieve a 10-year lifetime.