Research Of Microwave Active Devices Based On Spoof Surface Plasmon

Natural surface plasmon polaritons are known as special surface electromagnetic waves at optical frequencies that exist at the interface of metals and dielectrics and decay exponentially in the direction normal to the interface.In order to apply surface plasmon polariton to microwave and terahertz frequencies,the concept of spoof surface plasmon polariton was proposed.Spoof surface plasmon polariton have a good development prospect in antenna,RF circuit and communication system.Based on the properties of spoof surface plasmon polariton,three microwave devices are studied and designed in this paper,which are two active components,a detector and a mixer based on discrete components,and a passive filter.The experimental results show that the simulation results are basically consistent with the measured results,which verifies the reliability of the design.1.In this paper a Schottky diode detector based on spoof surface plasmon polariton structure is reported.The detector is designed with discrete components,consisting of an input matching network,a Schottky diode and output filtering network.The proposed detector is designed using the step impedance section and ?/4 radial stub integrated in the circuit.Compared with the conventional microwave detector,this detector achieves low transmission loss with-30 dBm to 5dBm input power.Experimental results show that the proposed detector achieves 31% improvement of detection sensitivity with the high input radio frequency power and 95% improvement of the detection sensitivity with the low input RF power by the SSPP.The proposed detector is attractive in aircraft,vehicle and wireless communications for its miniaturization,low-cost and easy-fabricated with planar circuits.2.The design and measured characteristics of a microstrip rat-race mixer based on spoof surface plasmon polariton structure are presented in this paper.The single balanced mixer consists of a configuration of a rat-race hybrid-ring with four ports and two SMS7621-060 Schottky diodes.The mixer fabricated on a Rogers 4350 B substrate uses the step impedance section and ?/4 radial stub integrated in the circuit.When radio frequency signal at 24.01 GHz and local oscillator signal with the power of 10 dBm at 24 GHz are injected,a conversion loss of 8dB is obtained.Compared with mixers reported by other researchers,this mixer achieves low transmission loss.Experimental results show that conversion loss of this mixer is reduced by 30% and the driving power is reduced by 23%.The proposed structure is easy to fabricate with the PCB process without a complicated design.3.In this paper a filter based on spoof surface plasmon polariton structure is reported.Base on the high frequency cutoff characteristic of SSPP,this structure improves the performance of the outband suppression by creating transmission zeros.Compared with the traditional hairpin filter,this filter shows strong performance of the outband suppression.The suppression of this filter is reduced by 7dB at 0.5GHz in the lower sideband.The passband range of this filter is 36-39 GHz,the insertion loss is within 2dB.