Research On Miniaturization Of Microwave Wideband Receiving Frontend

In recent years,with the rapid development of microwave and millimeter wave technology,miniaturization,high integration,multi-function,low cost,high reliability and other characteristics have attracted much attention and have been widely studied.Three-dimensional structure can easily integrate different packages of active devices and other passive circuits in a single package to improve system integration and achieve the purpose of miniaturization.The receiver front-end is an important part of radar receiving systems,so the high integration and miniaturization of the receiver front-end are of vital importance to the relevant performance of radar systems.This paper mainly focuses on realizing high integration and miniaturization of the wideband receiving front-end by using three-dimension structure.This paper briefly describes the recent researches about miniaturization of transceivers at home and abroad,and then introduces receivers,PLL circuits,LTCC process and its characteristics.On the basis of what we introduced,we finish the simulation and optimization of transmission lines and transitions in the LTCC substrate,simultaneously,we design the vertical-transition structure between LTCC substrate modules by using BGA(Ball Grid Array).And then we finish the design and simulation of receiver front-end with double-conversion solution which applies a fractional-N phaselocked loop(PLL)frequency synthesizer as the local oscillator signal source.The RF conversion module and LO source module are assembled on two different LTCC substrates and are connected by the interconnection structure between LTCC substrate modules by using BGA.Thus,the receiver front-end is miniaturized by stacking active chips vertically.Finally,the PLL circuit and the receiver front-end are fabricated,assembled,debugged,and tested.The measurement results are analyzed in detail.The measured results show that the RF frequency is 30MHz-3GHz,receiving gain is greater than 34 dB,noise figure is better than 15.3dB,and spurious signal suppression is greater than 28 dBc.The total area of the LTCC circuit is only 20mm*20mm.