Microfluidically Loaded Wideband Frequency Tunable Antennas and RF Filters

Reconfigurable radio frequency (RF) antennas and filters have drawn growing interest to enable compact and light-weight multifunctional systems. Existing reconfigurable RF device design approaches that are based on material loadings, semiconductor and ferroelectric varactors, micromechanical systems (MEMS) switches and capacitors are today well-recognized to offer compact and cost-effective device implementations with high reconfiguration speeds. However, these technologies continue to exhibit limited performance in terms of key RF metrics such as power handling, frequency tunability bandwidth, efficiency, and frequency-agile capability. Consequently, alternative techniques that address the performance needs of reconfigurable RF devices continue to be highly desirable. This presentation focuses on novel reconfigurable RF antennas and filters realized by resorting to innovative microfluidic based reconfiguration techniques. The operational principles of these devices rely on continuously movable microfluidic loads consisting of metal (in liquid or solid form) and dielectric solution volumes. The realization of the devices are carried out by utilizing microfluidics and microfabrication techniques with multilayered ultra-thin substrates to maximize the parasitic loading effect of the microfluidic loads for achieving high reconfiguration performances. It will be shown that the presented microfluidic reconfiguration techniques offer significantly improved frequency tuning range (>4:1 and >2:1 in monopole antenna and filter topologies, respectively) without suffering from excessive loss factors and high power handling issues observed in conventional semiconductor based implementations. Compact wideband frequency tunable antenna and filter realizations strategically designed to handle >15W continuous RF power will also be presented.