Research On Key Technologies Of Multi-beam Based On SiP

The multi-beam antenna systems can improve the detection performance and antiinterference ability of a radar.It can also meet the requirements of the high-speed data transmission,as well as the connection of the ultra-dense termination.Therefore,the multi-beam antenna systems play a huge role in the military and civilian fields.With the increasing requirement of the miniaturization or integration for the electronic systems and the development of the advanced electronic packaging technologies,it is of great significance to carry out the miniaturization,integration and light-weight Si P（System in Package）researches for the multi-beam antenna systems.In this thesis,the operating principles of the multi-beam antenna systems are studied.According to the principle of RF beamforming in the active phased array,a system-inpackage method based on high-temperature co-fired ceramic technology is used to design and process an 8×8 multi-beam receiver at Ka-band.For 8-channel antenna signals,this component can receive 8 beams at the same time.It can also control the beam direction and side lobe level of each beam through 8 groups of 8-channel independently controllable phase-shift attenuation channels.Therefore,the capacity for the flexible beam control is achieved.The size of the component is only 43mm×19mm×2.9mm.The overall ceramic package substrate is co-fired by 33 layers of HTCC（High temperature cofired ceramic）ceramic sheets,in where the 8 pieces of the BGA（Ball Grid Array）flipchip multi-function chips and 8 pieces of the eight-way synthesizer chips are packaged.The two functions including amplitude/phase control and beam forming are integrated in the integrated tile structure.At the same time,the capacity of simultaneous reception for the 8 beams is realized.In this thesis,based on LTCC process,a complete assembly and experiment of a modular multi-beam receiving component is carried out.To effectively reduce the number of layers used in the substrate,a transition method is proposed for utilizing the 30Ω nonstandard impedance as the signal transmission inside the integrated HTCC component and make it matched to the 50Ω standard impedance at the external port.A broadband transition structure for the BGA,which is located at the bottom of the chip cavity of the HTCC substrate,is designed for the packaged multifunctional-chip.In addition,the performance and program verification of the multi-function chip are carried out on a single board.The measured results of the multi-beam integrated HTCC components show that the single channel loss corresponding to the eight receiving beams is in the range from 3.5d B to 6.5d B,at the operating frequency band from 27.5GHz to 30 GHz.The measured amplitude difference is better than 1.5d B.The attenuation RMS error and the phase shift RMS error is less than 1d B and 3°,respectively.The additional phase shift caused by attenuation is better than 10°,when the additional amplitude change caused by phase shifting is better than 1d B.The isolation about 50 d B between the two beams is achieved.