A microfluidically-switched CPW folded slot antenna

A microfluidically-switched CPW folded slot antenna is proposed. The switching technique is based on employing the capacitive loading effect of two fluid metal channels placed on top of the CPW slot antenna. By filling the channels with Galinstan, the antenna is reactively loaded and as a result the resonant frequency of the antenna is reduced. Implementation of the microfluidically-switched antenna is realized using the common PCB techniques and PDMS structures. The PDMS structures including the micro-channels are bonded to the circuit board using a very thin layer of spin-coated PDMS employed as the bonding layer. A frequency switching ratio (f_TR=f₂/f₁) of more than an octave (2.6-5.5 GHz) is obtained for the proposed antenna. The antenna shows similar radiation pattern with high purity (Co- to Cross polarization level > 15dB) for both frequency bands.