CMOS Micromachined Inductors With Structure Supports for RF Mixer Matching Networks

This letter presents the comparison of three novel structure supports for on-chip complementary metal-oxide-semiconductor (CMOS)-based micromachined inductors by using a proposed two-step maskless post-CMOS process. A 3-D electromagnetic inductor simulation model is established and calibrated with inductor fabrication. The proposed inductors are applied in the matching network of the double-balanced Gilbert mixer to improve the performance and the mechanical stability. The mixers, with and without micromachined process inductors, are fabricated in a 0.5-mum CMOS process and compared in this letter. The measurement results show a 28.12% increase in conversion gain, a 31.7% improvement in third intercept point, and a 44% reduction in the noise figure.