Research Of Tunable Phase Shifter Based On Composite Right/Left-handed Transmission Line And Ferroelectric Materials

Left-handed materials were made to know at the 1960s, but until the beginning of this century it realized the practical application from theory. Composite right/left-handed transmission line (CRLH-TL) is a successful application of left-handed materials, which give full play to the pure left-handed materials, while having the traditional right-handed materials properties at the same time. If we can find a control method to enable flexibility to switch between the two properties, it will be able to produce great value.This paper is mainly on a phased array antenna used the tunable phase shifter, which is able to achieve convergence of the antenna radiation beam and the direction of the control, also reducing the antenna beam width, improving the antenna directivity. The method is to use the CRLH-TL and ferroelectric materials. Then design a kind of coplanar waveguide and transmission line phase shifters, and use software HFSS to simulation the phase shifts. The CRLH-TL's role is to provide a variety of special phases, and the ferroelectric materials is to make it able to choose those phases. With those to methods, it is able to achieve the diversity and flexibility control of phases, the final aim is to meet the needs of array antenna.After discussing the relevant basic theory of left-handed materials and ferroelectric materials, the main individuals includes:(1) Tunable phase shifter design of transmission line structure. (2) Tunable phase shifter design of coplanar waveguide structure. (3) In The study of the adjustment of structural parameters'effect of the transmission line structure tunable phase shifter, using the HFSS simulation software for research. (4) DC feed design of the two types phase shifter mentioned above.Compared with traditional phase shifter, the biggest advantages of this design is the ability to provide advanced output phase, while in advance can be controlled through the phases. As using CRLH-TL technique, this phase shifter design also has small size and low power consumption. Through simulation, the two types phase shifters are able to produce a special advanced phase, and electronically controlled tunable. It is expected that if this phase shift is applied to the design of phased array antenna, it will be able to greatly enhance its performance.