标题: zt:?¨??????ר?????????????·??????????????
smile
版主
Rank: 7Rank: 7Rank: 7


UID 17
精华 1
积分 238
帖子 238
阅读权限 100
注册 2004-2-16
状态 离线
发表于 2004-3-17 11:35  资料  个人空间  短消息  加为好友 
23??GSM ???úPCB?è??
  ?? ?? ????ר??GSM???úPCB?è???????????ó???????
????  ???úPCB?è????????????????????·???????°???????????????RF?????·???ò????????°??????????????????????????????????·???ò????RF???·?????????·?? ?°?????????·????°?????×????·?????ü?????÷?????????è???è?ó??  
1???×??±?????RF??·?RF?????·??°?×???×????±?????????ò??RF?????????????°×è???è????·?????????  
2???ò??°??????????????è?????¤???×(blind/buried via)??????×?????????  
3??×????°?????????·??×?????????±????ü??×????·??RF???·???ú?ú???????ó?? ???????ó×??????à????????????ground guard trace??????????  
4?????±×???????·????? ???????????·????????±?×?????????±????ü???·???????ù??????  
5??×????÷???·???ò?????????÷???÷?·??(return current path)?? ±?????????????????????
24??pcb?è?????è??×?????????????
??PCB?è???±?ù??×???????????×??????ú?·?????????????????ó??×????·??·??????·??×???????·??????à?????ù????????????????????×????????ò??  
1??PCB?????????¨??°ü?¨??????????????×???????°??????÷×???????×???·??ò???????????á?°?ì?????·????????????·?????????  
2???????????à????×????????×(via)???????í???????ó??  
3?????????????·?????ò???????????????ò??????×????????×???????????????????à?±?ó????????  
4?????????ú?ú?¤?§?????ì?¤?????è?¨DRC (Design Rule Check)?°???????à?????è??(????????)?????ü???????à???ù??×????????????????·??????????????????????????±???????×????·????·?×???×?????????×è?????????????·????????×????¤?????¨??
25??????????PCB?è??????EMC??EMI????
??????????PCB?è???±???????????í???????????????è??????EMC??EMI???ò?????ì?é?????è??????????????·?????????EMC??EMI?????ò?????ù?è?????ò????????????CADENCE???????í????
??????°?EMI/EMC?è???±?è?????±????·???(radiated)??????(conducted)????·???. ?°???é????????????????·?(>30MHz)?ó???ò????????????·?(<30MHz). ?ù????????×?????????????????????·?.
????????EMI/EMC?è??±??????????????±???????????÷????????, PCB?ü????°???, ???????ú??×?·¨, ?÷??????????, ???????????????°????????°???, ???ó?????ò?á??±???°?, ??????±?. ?????±???ú?ú?÷?????????????????ü???????????÷, ????????????×???????×???????×è??????????????????????????·???, ?÷???ù???????????±??(slew rate)??????????????????·?, ??????????(decoupling/bypass)?????±×??????????ì????·?·????è?ó???????????????ù. ?í??, ×??????????????÷?????÷?·?????????·??????????(?????????·×è??loop impedance??????)??????·???. ????????·?????????·????????????????ù??·??§. ×??ó, ???±??????PCB??????????????(chassis ground)??





Smile And Retain Smile Forever
顶部
smile
版主
Rank: 7Rank: 7Rank: 7


UID 17
精华 1
积分 238
帖子 238
阅读权限 100
注册 2004-2-16
状态 离线
发表于 2004-3-17 11:36  资料  个人空间  短消息  加为好友 
26??????PCB?è??????×è??????????
??????????PCB?è???±????·???·???????????×è??????????????PCB?????¤?¤????????×è????????????·?????·????????????í?????è???±???ù?????????????????í??????IBIS???????????????????á??±???×??·??IBIS???????????????????????????ó?à????????×??·?????°?ì·?????????????
???????è??????PCB???·?±??×è?????????è????????????????×è?????ú×???·????????????????? ??????×???±í????(microstrip)?ò????(stripline/double stripline)??????????(???????ò????)???à????×????í????PCB???????ù?á?°?ì×?????????×è???????????????????????ó?????·?¨×è????????°?·????í???á?ò???·?????ò?ù?????????§??·¨??????????·¨??????????×è???????????????é???????±?ò?????í?????????¤??????terminators(????)??????????×è??????????×???×è???????????§?????????ù±???????????·?·¨?????????±????×???±???×è??????????·??ú??
IBIS??????×??·???±???°?ì??·??????á?????ù±???IBIS????????????????I/O buffer???§???·??????????×???????°?????SPICE????×??????? (?à???????????? ?????????à)????SPICE??×????????????ì???????????????ù?????ù?????÷???????????§???á??????SPICE??×?????????????????×????ó??IBIS????????×??????á???????ì????????????????????A?§?????÷???????????????????á???????÷??×??·????×??????ò?????????ü???á±??????ü???????????÷???????????¤??×??????????????§???ù?á????IBIS??×??·?? ???????????ó???§???????????ù±???????????
27?? PCB?è???¤??±???
?????????????????????????????????????·?¨???¨??????????????????×????·?¨???¨????????????????????????×??ì?????·?¨???¨???????????????????°PCB?è????????EDA?¤??????????????????±??¨??·?????????·?·?±????÷??
????????±?????????????????·¨??????±???EDA?¤????????????±????????í????°????ù????·????????????÷???????ò????????????  
?????????·?è????INNOVEDA ?? PADS ??·??????í??????????????·????í?????????à?è???ù?ù??????70%??????????????×????????·?è????????????×??ì?????·??????Cadence??????·?°?????????????????±????????í?????±??Mentor??????????·??????í??????±????ü???è???÷?????í·?????????×???????????  
??????????????????????
28????????/??·?????????????????
  ?????±??????????????????RF?????????????????±???????±???¨????????????/??·??????????¨?????í?????????¨??·????????????????????????ù?????????????????????°?????á?????¤??±??????±?????????????§???????????¨?ú?????ò??????????×?????????????????????×??ó???á?????ú???????????????????????¨?????????????°????????????·????·????????????????ר????·???????????
????????RF?????????????????±?????????é?????????????????????ò?è??×?×?????·????????à????????????????·?·¨??????????°?????????????????????????????????????·?·¨??0??????RF?????????????±???????±???×??????????????????·?????????????????????????????????????????  
1??????RF?????????????±????????????????????????????????±???????·???????????????  
2??????×????????????????????à???¨???ó??????????????????,???????????????ú????????  
3?????????????¨??·?????????????





Smile And Retain Smile Forever
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