Microwave Sensors Based On Plasmonic Metamaterials

Low-cost,high-sensitivity and non-invasive microwave integrated sensors are of important interests for the development of the economic and sociaty.This thesis focus on the research of microwave microfluidic sensor with high sensitivity based on plasmonic metamaterials.The main research contents and achievements are summarized as follows:1.A Fano resonant microwave sensor composed of the rectangular substrate integrated waveguide(SIW)and the ultra-thin grooved ring resonator is proposed.By etching a resonant ring through which the SIWcouples with the ultra-thin ring resonator,the asymmetric Fano resonance is generated.The microfluidic sensor based on SIW and spoof LSPs resonator is highly sensentive to the change of materials under test.2.An ultra-thin grooved metal-insulator-metal(MIM)ring resonator with microstrip coupling arms at the back is proposed.Byadjusting the position and length of the coupling arms,specified resonant modes can be effectively coupled out from the resonator.By introducing low noise amplifier(LNA)at the microstrip coupling arms to compensate losses of the structure,selective amplification of spoof LSPs is firstly realized and the magnitude of the selected spoof LSPs mode is increased by 17 d B.3.An active Fano resonance microwave sensor is proposed,where asymmetrical Fano resonance is excited due to the coupling of two spoof LSPs resonators stacked vertically.By introducing LNA chip into the slot of the upper grooved ring to compensate the losses caused by the structure itself and the highloss liquid under test.The quality factor(Q)is increased 37 times and the resonance intensity(RI)of the sensor is significantly improved from 19.89 d B to 37.42 d B.The experimental measurements show that the limit of detection of the glucose sensor is as low as 10 mg/dL.