A Novel Frequency Reconfigurable Filtering Antenna Loaded with Microfluidic Structure

A new design approach to reconfigurable filtering antennas is proposed in this paper. A first-order filter is employed in the feeding network of a monopole antenna, which is series-coupled with the feeding line. A microfluidic channel engraved on polydimethylsiloxane (PDMS) is placed on the top of the filtering network. By loading different materials in the microfluidic channel, the operating frequency of the proposed antenna can be tuned effectively. To verify the proposed concept, water-ethanol solutions with different concentrations are injected into the channel to change the dielectric constant of the area covered by liquids, and a frequency tuning range from 2.32 GHz to 3.27 GHz of the filtering antenna is achieved. Compared with other traditional frequency reconfigurable filtering antenna design methods, this design can effectively reduce the insertion loss and design complexity caused by the introduction of switching circuits and components.