On the operating mechanisms of flexible microwave inductors and capacitors under mechanical bending conditions

Abstract

Flexible microwave passive components play an important role in flexible integrated circuits, especially for high-speed wireless communication systems. It is clear that bending can have a significant impact on the flexible components' performance. However, an analysis of the physical mechanisms of flexible microwave passive components under mechanical bending conditions has not been completed. In this paper, we describe a study of the performance variations and operating mechanisms of flexible microwave inductors and capacitors under mechanical bending conditions. Flexible spiral inductors and metal-insulator-metal capacitors of various dimensions were fabricated on plastic substrates and measured under different mechanical bending conditions. Modeling of the flexible components was conducted. The influence of mechanical bending on flexible inductors and capacitors was characterized based on experimental and modeled results. The underlying operational mechanisms of flexible inductors and capacitors under bending conditions are discussed using the distributions of the electric and magnetic fields from the model. In addition, the performance variations with different component parameters (e.g. the metal and substrate materials, the thicknesses of the metals and dielectrics) were studied under bending conditions. The results are helpful for the use of flexible microwave passive components in flexible microwave monolithic integrated circuits.