Design Of Microwave Thin Film Phase Shifter

Microwave phase shifter is a device which is used to change the phase of microwave signal.It is widely used in the field of microwave communication and phased array radar and so on.In this paper,the principle of microwave thin film phase shifter is studied theoretically,and the microwave thin film phase shifter is designed,the influence of the size change of each part of phase shifter on the performance of the device is discussed.Ferrite thin film phase shifter is designed according to the characteristics of ferrite magnetic material.The permeability of ferrite shows the tensor characteristics,intensity and direction when the external magnetic field changes when the permeability of ferrite will be changed,thus changing the propagation constants of ferrite,also change the propagation characteristics of electromagnetic wave,resulting in a phase shift,phase shift by the size of the constant magnetic field control.Materials used are YIG(yttrium iron garnet)and GGG(gadolinium gallium garnet),the conductor material used is gold.The principle and structure of several kinds of thin film phase shifter are analyzed,and a ferrite phase shifter based on coplanar waveguide structure is designed.According to the theory of microwave planar transmission and the characteristic analysis of the rotating magnetic material,the wave propagation equation is obtained,and the size of the phase shifter are calculated.The ferrite material,the substrate material and the metal conductor were screened,and the transmission characteristics of the phase shifter were studied.The design,simulation and optimization of the phase shifter were made.The use of HFSS software on the performance of coplanar waveguide structure is simulated,the phase shifter is the size of each part of the optimization,the influence of the parameters such as the width of the center conductor,the gap of the coplanar waveguide,the thickness of the film and the thickness of the electrode on the device performance were studied.The results show that the designed phase shifter achieves better performance at the center frequency of 50 GHz,the insertion loss is less than 2dB,the voltage standing wave ratio is less than1.5.