EMI Suppression of MEMS Honeycomb-Shaped Inductor on Oscillators for Wireless-Powered IC Design

This paper shows the operation of honeycomb-shaped inductors with or without micro-electromechanical systems (MEMS) post-process in Ku-band and their application to VCOs in terms of circuit performances like crosstalk and injection pulling effects. The unique layout pattern of honeycomb-shaped inductor can provide almost omnidirectional electromagnetic interference (EMI) suppression to adjacent noise interferes. In this work, MEMS process is adopted to remove the silicon substrate for improving the inductor quality factor. The honeycomb-shaped inductors either with or without MEMS postprocess and the single-turn octagonal inductor are implemented to Ku-band VCOs operated at 17 GHz, respectively, with the same dc power consumption of 5.29 mW at V
_DD
= 1.8 V, as an experimental set for comparison. The experiment results indicate that the honeycomb-shaped inductor exhibits better injection pulling mitigation than the single-turn octagonal inductor by more than 15 dB. This feature would be helpful to the design of wireless-powered sensor integrated circuits (ICs) with more EMI suppression capability in 5G communication environment.