Research On The Key Technology Of SAR Data Processing Module Based On MCM

Synthetic aperture radar(SAR) is an important way of detection with all-weather feature, many areas have a clear demand for it. Recently, device miniaturization technology is well developed, it is an achievable task to minimize the SAR for small carriers.The key technologies to achieve SAR miniaturization are multi-chip module(MCM)technique and Low Temperature Co-fire Ceramics(LTCC) technique. Multi-chip module technique is of high efficiency,which assembles many electronic components on a high density interconnect substrate of small size. Substrate design is the key of MCM. Low temperature co-fired ceramics(LTCC) substrate is of low sintering temperature, steady sintering shrinkage rate, low dielectric constant, low resistivity, unlimited lamination number,which contributes to its design.MCM assembles many electronic components on a high density interconnect substrate of small size, results in small components spacing and high routing density, there will inevitably lead to the signal integrity(SI) problems. So it is necessary to carry on signal integrity simulation of MCM,and guide the design of MCM with the simulation result. This paper mainly studies the influence of the vias inside the substrate on signal integrity.Firstly,this paper build a electric model for the vias. The model is a PI shaped circuit including a parasitic capacitance and the two parasitic inductances. Then this paper studies the influence of the vias on signal integrity through simulation for this model under two circumtances,via located in the middle of the signal line and via located in the end of the signal line. The simulation results show that effect of vias on signal integrity increases with the increasing of parasitic capacitance and inductance. The influence on signal integrity is serious when the thvia is positioned at the middle of signal line. Therefore, we should thoose vias with less parasitic effects and reduce the number of vias in the MCM.This paper aims at the miniaturization of SAR under the consideration of signal integrity, studies the ways to redesign and realize the data processing module of SAR using MCM technique. Firstly, redesign the structure of the original data processing module to meet the need of 3D-MCM. The original data processing module is designed into the structure of 3D MCM with four parts: the protective shell, the top two 2D-MCM, the bottom 2D-MCM and vertical interconnection parts.Then set up symbol library,package library,draw schematics and design layout with Cadence for the module with new structure and extract data for manufacture. At last,realize the 3D-MCM data processing module with LTCC process with manufacture data.