High performance MEMS 0.18 μm RF-CMOS transformers

This work presents a micromachined RF-CMOS transformer fabricated in a commercially available 0.18μm CMOS process. Maskless micromachining post-processing is used to remove oxide and substrate material from around the transformer, reducing parasitic effects and improving the performance of the transformer. Index Terms — baluns, CMOS integrated circuits; MEMS, maskless micromachining, Q enhancement, radio frequency integrated circuits, RF-CMOS transformers.