Differential filter based on artificial surface plasmon

Abstract

The invention discloses a differential filter based on artificial surface plasmon. The function of a differential wave filtering is achieved by means of a metal grating ring and mutual coupling and interference between a first straight metal grating structure and a second straight metal grating structure. The straight metal gratings and the metal grating ring are metal straps which are printed on a medium substrate, the thickness of each metal strap is nearly zero, the size of each metal strap is small, the length and the height of a unit structure are smaller than the operating wavelength, and the thickness of the unit structure is far smaller than the operating wavelength. Surface wave propagation can be bound in the size of deep sub-wavelength surrounding the metal straps, and efficient transmission of energy can be achieved. A dispersion curve of the metal surface can be changed by means of control over the depth, the width and the periodicity of a surface groove of a metal grating structure and control over distance between each straight metal grating and each metal grating, and the metal grating structure which meets the requirement of a working frequency is designed. A coaxial line inner conductor which extends outward is taken as a metal line to stimulate surface waves on the metal grating structure. The differential filter based on the artificial surface plasmon has the advantages of being wide in bandwidth, not obvious in internal dispersion of a pass band, stable in performance, and applicable to different wave bands such as microwaves, millimeter waves and Terahertz waves by means of scaling of structural parameters.

Description

technical field [0001] The invention belongs to the fields of communication, data storage, surface technology and the like, and in particular relates to an insertion / addition filter based on artificial surface plasmons. Background technique [0002] Wavelength division multiplexing (WDM) communication technology is currently the main means of information transmission in Haiti and land long-distance trunk lines. As a key device in the WDM system, the performance of the add / drop filter with wavelength selection capability will have a crucial impact on the entire system. People have proposed a variety of add-and-drop filter structures, but it is still difficult to realize a small, efficient and easy-to-integrate filter. [0003] Surface plasmons (surface waves) are not limited by the diffraction limit, so they can be used to construct miniaturized components, and have important applications in surface technology and communication technology. By using two-dimensional planar pl...

AI Technical Summary

Problems solved by technology

People have proposed a variety of add-and-drop filter structures, but it is still difficult to realize small, efficient and easy-to-integrate filters

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