Investigation ofp-n junction inductors for RF CMOS circuits.

摘要

Inductors are crucial elements for high performance RF circuits. In this dissertation, we investigate the p-n junction inductors utilizing interband tunneling and avalanche mechanism to generate inductive effects. Compared to passive inductor, the higher quality factor (Q) for the p-n junction inductor can be attained. Due to this p-n junction inductance coming from the mixed tunneling and avalanche mechanism, the Q and noise performance is a tradeoff problem. Consequently, the Si bandstructure, the tunneling generation rate and the avalanche generation rate were probed to attain the design concepts for the p-n junction inductor. The mixed tunneling and avalanche effect complicates the inductor design for the high Q and low noise. In this research work, one new method to unravel these two effects with non-local effects involved was successfully developed for the first time since 1950's. The tunneling generation rate characteristics extracted from this new method showed the individual indirect tunneling and direct tunneling rate for the first time. This tunneling generation rate is consistent with the other results after adding our new extracted avalanche multiplication factor to our new extracted tunneling generation rate.; The tunneling generation rate and avalanche multiplication factor is applicable to design the high performance of the p-n junction inductor. A 2.4 GHz LNA with the p-n junction inductor in 0.35 mum CMOS were presented in this research. The first stage of the proposed two stage LNA provides input matching, low noise and sufficient gain to suppress the noise from the second stage. The second stage with the high Q of the p-n junction inductor provides enough gain. The two stage LNA with this new design p-n junction inductor has 2.83 dB noise figure and 23.32 dB gain.