Assessment of PDMS Technology in a MIMO Antenna Array

This letter assesses the use of a flexible multilayered polydimethylsiloxane (PDMS) substrate in a multiple-input-multiple-output (MIMO) antenna array for WLAN applications at 5.8 GHz. The use of the innovative polymer-based PDMS technology features favorable mechanical properties such as flexibility, water/dust resistance, and optical transparency. Besides that, PDMS also has a relatively low loss tangent. All these properties are very relevant for future (wearable) WLAN MIMO antennas. The proposed 2 x 4 antenna array and its rear ground plane are embedded in a multilayered PDMS substrate and fed by two 50-Omega coaxial ports. It is found that the multilayered PDMS substrate may yield a design with excellent MIMO parameters. The mutual coupling is better than -30 dB, the envelope correlation coefficient (rho) is in the order of 0.001, and the efficiency is 72%. A high gain of 11.5 dB is achieved.