A 2.45 GHz CMOS up-conversion mixer design utilizing the current-reuse bleeding technique

Abstract

A 2.45 GHz double-balanced modified Gilbert-type complementary metal-oxide-semiconductor (CMOS) up-conversion mixer design utilizing the current-reuse bleeding p-channel mos (PMOS) transistors is examined thoroughly based on simulations to demonstrate many advantages achievable when adopting the current-reuse bleeding technique in the mixer design. It is shown that the current-reuse bleeding technique certainly provides benefits in terms of gain, linearity and noise characteristics. In the mixer incorporating the current-reuse bleeding technique, the conversion gain improves monotonically with more bleeding. The linearity also improves with bleeding by a noticeable amount when the voltage headroom is not adequate. However, with excessive bleeding, linearity degrades by the current-limiting phenomena which defines the optimal bleeding ratio. Noise performance also improves monotonically with more bleeding. Of all the benefits provided, the improvement in noise performance seems most valuable. The measurement of the fabricated chip based on the standard 0.35 mum CMOS process supports the validity of the analysis. The measured mixer performance is quite excellent, and the measured characteristics are in close agreement with the simulations, which demonstrates the adequacy of the modelling approach based on the macro models for all the active and passive devices used in the design.