The Study On High Performance Miniaturized Passive Devices Design Of RF Front-end

With the rapid development of modern wireless communication,especially the growth of the VLSI driving microwave circuits to the development direction of mininaturization,high performance and low cost.As an important microwave passive device,power divider undertakes the disbution and synthesis of signal and commonly in the microwave cicuit with cascading filter.Threfore,it is of great academic and engineering significance to study the microwave power divider with small size and high performance.This dissertation proposes some power dividers with different structure,which based on the principle of the quarter wave-length impedance transformer,filtering power divider and broadband coupled ultra wideband power divider.The main contributions of this dissertation can be summarized as follows.Firstly,based on the idea of quarter wave-length impedance converter,three power dividers based on stepped impedance resonator,parallel transmission line and miniaturized harmonic suppression coupled transmission line are presented,respectively.By combining ABCD matrix theory and matlab analysis,the initial design parameters are obtained.The correctness of the design method is verified by electromagnetic simulation and physical measurement.Secondly,Based on the theory of coupled reaonace and multimode resonator(MMR),two filtering power dividers based on short circuit quarter wave-length resonator and short stub load annular resonator are proposed,respectively.Further,based on the theory of coupled reaonace,the coupling between source and load is introduced to power dividers to improve the low frequency selectivity.In addition,a dual band multi-mode resonator is achieved by loading the stubs to the conventional short stub loaded resonator,based on this structure,a dual band filtering power divider is formated.Finally,a filtering power divider based on three ports broadband balun filter is proposed.The above circuits are verified by electromagnetic simulation and physical measurement.Finally,In order to meet the needs of ultra-wideband research,the broadband characteristics of microstrip to slotline transition structure are discussed,and the method of transforming the two port ultra-wide band filter based on this structure to the three port power divider is given.Moreover,the dual band power divider is extended to an ultra wide band power divider by using the broadband characteristics of microstrip to slot line coupling.Meanwhile,the incremental impedance line is further introduced to form a miniaturized ultra wideband power divider.Finally,to improve the contradiction between the return loss and isolation of the UWB power divider based on microstrip to slotline structure,a zero ohm resistor and a 100 ohm resistor are introduced to improve the return loss and isolation of the power divider in the microstrip to slotline to microstrip coupling mode.The above circuits are verified by electromagnetic simulation and physical measurement.