Symmetric 3D passive components for RF ICs application

Abstract

This paper proposes novel 3-D symmetric RF passive components, including inductors, transformers, and baluns. Layout areas of these components are drastically reduced by means of stacked structure while the symmetry of input and output ports is also maintained. The area saving of 3-D inductor is up 70 %. The 1:1 transformer shows less than 0.1 % inductance mismatch in a 18 GHz range, and K is up to 0.87 at 17 GHz. The 3-D balun manifests less than 0.8 dB gain mismatch from 5.25GHz to 6GHz and phase error is about 4degrees at 5.25 GHz according to measurement results. All the components are fabricated in a 0.18 mum standard CMOS process.