Research On Phase Shifter With Latching Structure Base On LiZn Ferrite

Phase shifter is one of the critical parts of phased array radar and ferrite phase shifter is characterized by huge power,good quality factor and so on in all types of phase shifter,which is widely applied in phased array radar.With the rapid development of phased array radar,the phase shifter is moving towards the direction of miniaturization,high-integration and good-performance.The traditional ferrite phase shifter can not meet the requirements of modern phased array radar.the development of Low Temperature CoFired Ferrite?LTCF?brings a new solution that solve the problem in modern phase shifter.The main research of this paper is to design new ferrite phase shifter for modern phased array radar,based on the technology of Low Temperature Co-Fired Ferrite.This paper unfurls the research by four aspects—material,device,technology and driver circuit.In the aspect of material experiments,the effect of sintering temperature,sintering location and heating rates on Lithium-Zinc?LiZn?ferrite material based on Fe₂O₃ and Fe₃O₄.The results show that the sintering temperature of the optimum processing condition of ferrite based on Fe₃O₄ is 1100?,which is 50 ? lower than that of ferrite based on Fe₂O₃,and B_m,B_r,B_r/B_m and Hc of ferrite based on Fe₃O₄ are respectively 265 mT,226.84 mT,0.86 and 255.76A/m.So the characteristics of microwave sintering of LiZn ferrite material based on Fe₃O₄ is better than LiZn ferrite material based on Fe₂O₃.In the aspect of device,three types of ferrite phase shifter were designed and simulated by ANSYS HFSS 15,respectively by stripline,microstrip and substrate integrated waveguide and this paper make a summary of these shifters.The characteristics of all these shifters are miniaturization and ease of integration.The shifter based-on substrate integrated waveguide has highest power capacity and best quality factor.The shifter based-on stripline has minimum size.The shifter based-on microstrip has highest reliability and easiest processing.Finally.this paper choose the shifter based-on microstrip to process.In the aspect of technology,this paper prepared 5kg raw ferrite material by solid state method and the raw LiZn ferrite phase shifter substrate was processd by LTCF processing line.The results of seven experiments about raw substrate sintering condition indicate that we should be careful to choose suitable weight?750-950g?on the substrate and sintering temperature?895-910??.In the aspect of driver circuit,according to basic principles of ferrite phase shifter,this paper design,process and debug a driver hardware circuit based-on Field Programmable Gate Array and writing,debug code by Verilog hardware description language.At last,the verification and test of the code,driver hardware circuit and ferrite phase shifter by oscilloscope and Vector Network Analyzer in this paper.The results show that maximum phase shift of phase shifter 1-1,2-4 and 3-2 is 370.82°,282.75°and 20°,the return loss and insert loss at 8GHz to 11 GHz of phase shifter 3-2 is lower than 13 dB and higher than 6dB.