Microfluidically Controlled Frequency-Tunable Monopole Antenna for High-Power Applications

A microfluidically controlled frequency-tunable monopole antenna with high RF power-handling capability is presented. Different than previous work, the frequency tunability of this monopole is achieved by using a movable metallized plate inside a microfluidic channel. The monopole is capacitively coupled to a feeding microstrip line through a 12- μm-thick benzo-cyclobutene (BCB) insulator that is used to seal and bond the polydimethylsiloxane (PDMS)-based microfluidic channel to the feed board substrate (RO4003C). It is shown that the presented reconfigurable monopole implemented with the metallized plate, low-loss BCB insulator, and RO4003C board exhibits 200% more power-handling capability as compared to prior implementation that relied on liquid metal, liquid crystal polymer, and RO5880 substrate. The presented monopole provides continuous tuning in the 1.7-3.5 GHz range with a tuning ratio of ~ 2:1. The RF power handling of the antenna is demonstrated through the agreement between multiphysics simulations and experiments conducted under high RF power excitation. The liquid metal free nature of the antenna and using BCB to bond the PDMS-based microfluidic channels with the printed circuit board substrates offer a new approach for realizing reconfigurable devices with higher efficiency and high power-handling capability.