Design and Analysis of CompactSubstrate-Integrated Waveguide (SIW)Cavity Resonator Based MicrofluidicBiosensor for X-Band Applications

Abstract

Biosensors are compact miniaturized devices to measure the biologicalsamples based on the molecular structure and convert the sameto electronic signals. The substrate Integrated Waveguide (SIW) cavitybased resonators loaded with a circular cavity can be used as a biosensorin a non invasive manner to detect the biological tissues in the sample with better efficiency and miniaturized structure.The biosensingsamples may vary from proteins to enzymes which has gained ahuge response in the industries likes medical, agriculture, food processingindustry and many more over the decades. The substrate materialof antenna is designed with Rogers RT/Duroid 5870 which has thedielectric constant of 2.33. The Rectangular patch antenna is thenloaded with the SIW vias for an enhanced performance of S parameterfrom -17.21 dB to -44.88dB operating at the X band (8 to 12GHz) frequencies. The microwell made from the Polydimethylsiloxane(PDMS) material is inserted into the patch infrom of circularslot to achieve the biosensing application. The microwell based SIWcavity is then simulated for different diameters of PDMS to improvethe S11 parameter and Voltage standing wave ratio. The fabricatedantenna is tested to work in the TE110 mode at a resonant frequencyof 12.12GHZ with a improved return loss characteristics of -42.45 dB