Fluidics in Microwave Components

Thanks to the efforts of various research groups over the past decade in the area of tunable microwave passive components, the idea of tunability has become very well established within the RF/microwave community [1]-[5]. Many different designs have shown that tunable microwave components can improve the performance of a radio system in many ways. The tunability of microwave components has been realized using semiconductor devices (such as varactors or p-i-n diodes) and microelectromechanical systems (MEMS) devices. While these offer many advantages, such as high-quality factor and high-bandwidth operation (mainly for MEMS devices) and fast switching speeds (mainly for varactors and p-i-n diodes), they come with two major drawbacks.