A Novel Multi Frequency Miniaturized Microstrip Antenna Design Based On Capacitive Coupling LHMs

Metamaterials are artificial periodic or aperiodic structures which can be designed to display specific electromagnetic properties of composite materials not commonly found in nature.In recent years, metamaterials with both negative permittivity(ε) and permeability(μ), more commonly known as left-handed materials, have been widespread concern in the scientific and engineering communities. The basic electromagnetic properties and the physical realization of left-handed materials are based on a transmission line approach to research,which provides an efficient design tool for the application of left-handed materials. In a sense, parasite right-handed effects of the composite left / right hand transmission line structure is the form of realization of left-handed materials commonly whicn shows a great potential in multi-frequency miniaturized antennas, filters and other new microwave devices.This paper mainly adopts CRLH TL to design the antenna, which is aimed at improving the miniaturization of the left hand antenna and extending the bandwidth of the left-hand antenna through the dual mode fusion technology.The antenna structure is designed based on the theory of transmission line and circuit model is relatively simple, less interference and easy to process. The main research work and results of this paper can be summarized as follows:Firstly, we designed a new multi-frequency miniaturized microstrip antenna based on capacitive coupling of a left-handed material. The physical structure of the antenna is novel, and the left hand capacitance is coupled through the gap between the two radiating patches, which influences the frequency of the antenna mode.Antenna has three operating modes:Negative order resonance、Zero order resonance and Positive order resonance. By adjusting the distribution parameters,,the zero order resonance and the positive are merged into a single pass band to obtain broadband. In order to improve the effect of the coupling capacitance, the antenna structure is improved, so that the effect of the left hand coupling capacitance on the antenna pattern is more obvious. On this basis, we opened a U-shaped groove around the hole at the bottom of the patch.The parameters of the left hand reactance can be increased without increasing the physical size of the physical to reduced resonant frequency,which make the antenna more compact size. The antenna is processed and tested, and the test results are in good agreement with the simulation results.Secondly, on the basis of references, we design a compact three mode metamaterial monopole antenna with curved line structure using the most common left hand interdigital capacitor and meander line inductor. The antenna does not require vias, simple structure, easy processing, and also has three operating modes: NOR、ZOR and POR. by adjusting distribution parameter,the zero order resonance and the positive are merged into a single pass band to obtain broadband and dual band. The antenna is processed and tested,and the test results are consistent with the simulation results.Finally,the full text is summarized and the development prospects of the left hand materials are forecasted.