Abstract
Based on the device reliability analysis, we extend the reliability analysis to the circuit level and predict the reliable operation time of the mixer circuit operated in W-CDMA System. The mixer circuit functions in both analog and digital modes. The input signal to RF Port comes from the antenna and its magnitude is typically less than –50dBm. This makes the devices of RF Port operate in analog mode. The major degradation mechanism appeared in this stage is the Channel Hot Electron Effect, since device are biased in saturation region. For LO Port, transistors serve as a switch, similar to the digital operation. This condition makes transistor in LO Port suffer high gate stress. Therefore, the degradation mechanism appeared in the LO stage mainly due to F-N Stress. Considering the Channel Hot Electron and Fowler-Nordheim Stress, a sub-circuit degradation model with operation time to predict the device degradation after suffering stress is proposed. Apply the model to the mixer circuit, simulate of change in Conversion Gain and IP3 of the mixer with operation time can be obtained. A brief discussion of the minimum requirement of the mixer circuit used in WCDMA & Super-Heterodyne Receiver Structure is proposed and the reliable operation lifetime extension can then be defined.