Research And Application Of The Local Substrate Integrated Artificial Dielectric Structures Coupled Line

As the basic unit in RF circuit, coupling lines are widely used in coupler, filter, phase shifter and so on. Its analysis and design has aroused extensive attention. In recent years, artificial dielectric properties of the materials are used to alter the media,for example,by adding metal conductor arry to increase the effective dielectric permittivity of artificial. Substrate intergrated artifial dielectric medium can increase the effective dielectric constant, and can be used in the microwave circuit in wireless communication systems whitch are improved towards miniaturization,high reliability, multi-functional and cost requirements.so coupled microstrip lines of SIAD are studied in this articleFirst, the article describes the basic theory of coupled microstrip lines, then introduces the even and odd analysis of symmetric coupled microstrip lines.Based on the analysis,the characteristics of symmetric coupled microstrip transmission with substrate integrated artificial dielectric structure is discussed.Second, asymmetric coupled lines are more flexible and convenient in the application. So the characteristics of asymmetric coupled microstrip lines of L-SIAD is studied.Then, by analyzing the L-SIAD structure of coupled microstrip lines, a microstrip to coplanar line transition of L-SIAD structure is studied in this article;an ultra-wideband coplanar line to microstrip line transition is designed.Finally, due to the left-handed characteristics of the transmission line of L-SIAD structure,witch means that it has a non-linear phase response, and the location of the zero-order resonance can be controled, a dual directional coupler is designed.