Research On Theory And Application Of Microstrip-type Spoof Surface Plasmon Polariton

Surface plasmon polariton (SPP) is electromagnetic excitations propagating at the interface between a dielectric and a conductor, evanescently confined in the perpendicular direction. It has extensive research and applications in the optical field. Spoof surface plasmon polariton (SSPP) is electromagnetic waves with similar dispersion curves as SPP and propagating at the periodic metal surface structure. It has been verified at the microwave and Terahertz band in recent years.Because of the unique dispersion characteristics, SSPP is very different from the traditional microwave transmission structures. There are two types of SSPP. One is three dimentional SSPP. Its process is very complicated and difficult and it is hard to be connected to two dimentional microwave components. The other is two dimentional SSPP or planar SSPP. Current planar SSPP is in single conductor form. It is difficult to be connected to the conventional double-connector transmission line. Therefore it is required to develop planar SSPP in double conductor form for seamless connection between planar SSPP and conventional transmission line. It is of significance to study the theory and application of a microstrip-type SSPP to meet the requirement in the thesis.Some important and valuable results are accomplished and listed as the followings:1. On the basis of studying SSPP, a new type of SSPP structure, microstrip-type SSPP, is proposed by combining the featrues of SSPP and conventional transmission line. Firstly, dispersion curve for the new SSPP and the impact of different sizes on the dispersion curve are analyzed. Secondly, its loss is calculated by the network analysis method. Then the mode conversion structure between the microstrip SSPP and conventional transmission line is presented based on the principle that the wave vector matching is also the impedance matching. Finally new structures are fabricated and mesuremed. Experiments valid the transmission efficiency of the new structures. It is shown that transmission loss is within 0.5dB below the cut-off frequency.2. Besides the "field" perspective, the new SSPP is analyzed from the "circuit" perspective. A scalable equivalent circuit model for this microstrip-type SSPP is proposed. A set of modeling and parameter extraction method are developed. The dispersion curves are matched fine.3. By using the feature that the field is confind within the metal surface in microstrip SSPP, the application of the microstrip SSPP in signal integrity is studied. It is found that the crosstalk could be effectively reduced for both coupled microstrip SSPP structures and differential coupled microstrip SSPP structures, comparing with conventional micrstrip structures. It provides a new efficient way to suppress the crostalk.4. Based on the field distribution of the new SSPP, it is explored to apply the microstrip SSPP in active microwave device. A novel OOK (On-off Keying) modulator is desined and fabricated by using the microstrip SSPP. The experimental results valid the design.