Microfluidic Filtering Antenna for Sensor Application

In this paper, an integrated filtering antenna is proposed as a microfluidic sensor. The filtering structure is implemented by two coupled split-ring resonators (SRRs), and connected with a circular patch antenna as feeding network. The microfluidic channel is engraved on a piece of polydimethylsiloxane (PDMS) block, which is located on the top surface of the SRRs to influence the resonant frequencies. A water alcohol mixture is used to test its performance, and a 180 MHz frequency shift of the resonant frequency is observed when the mixture of ethanol and water varied from 0% to 100%. Compared to other traditional microstrip microfluidic sensor antennas, the proposed filtering sensor antenna performs well in providing a low reflection coefficient, which makes it easy to observe the frequency shift.