Design of Microfluidic Reflectarray Elements for Multi-Reconfiguration Using Liquid Metal

Using an alloy of non-toxic liquid metal (Galinstan) is proposed to implement multi-reconfiguration in reflectarray elements. Reflectarray antennas are an interesting technology for dynamically controlling, simultaneously or individually, different properties of the antenna (beam shape and pointing direction, field polarization, and frequency of operation) according to the system’s demand. The use of liquid metal, which can potentially be used to re-shape the topology of the unit cell, along with advances in the micro-and nanofluidics field, provides more flexibility for efficiently implementing such multi-reconfiguration. A frequency-reconfigurable reflectarray element is based on the well-known aperture-coupled cell, and a phase-reconfigurable cell based on single-and multi-resonance dipoles is proposed at 28 GHz. One advantage of microfluidics is that the concept can easily be extended to much higher frequencies, where other devices start to be expensive, inefficient, or limited in terms of multi-reconfiguration. The microfluidic technology required to implement the dipole-based element is demonstrated using a microfluidic burst-valve chip. Additionally, a simplified RF proof-of-concept is presented using the well-known waveguide simulator technique from 15 GHz to 22 GHz (WR51). The results obtained constitute an important first step toward the implementation of multi-reconfigurable reflectarray antennas.