不知道有没有人看过高通的这个资料：Fundamentals of PCB Layout Guidelines for radi
今天偶然在网上收到这片文章，觉得不错，无赖我下载不下来，不知道有没有网友看过这个应用笔记，主要是讲手机射频部分PCB Layout。网站地址：http://bbs.cnttr.com/viewthread.php?tid=119218
This document provides general layout guidelines for phone designs using QUALCOMM
radioOne? chipsets, and supports those guidelines with detailed examples based upon an actual
reference design. The most critical aspects of PCB design are addressed – for RF functions in
particular – and should be taken into consideration throughout the development process.
This application note is intended for RF engineers currently (or soon to be) developing wireless
products that use a radioOne chipset.
1 Introduction...................................................................................................... 6
1.1 Purpose and intended audience..................................................................................... 6
1.2 Documentation overview.............................................................................................. 6
1.3 Terms and acronyms ..................................................................................................... 8
2 Layout Strategy ............................................................................................... 9
2.1 Parts placement and signal flow ................................................................................... 9
2.2 Shielding ..................................................................................................................... 12
2.3 PCB stack-up .............................................................................................................. 14
2.4 Using vias ................................................................................................................... 14
2.5 Grounding ................................................................................................................... 15
3 PCB Considerations...................................................................................... 16
3.1 Number of layers and PCB stack-up........................................................................... 16
3.2 Assigning functions to each layer ............................................................................... 17
3.3 RF traces: controlled-impedance transmission lines................................................... 18
3.3.1 Example microstrip design................................................................................ 19
3.3.2 Example stripline design ................................................................................... 20
3.4 Vias ............................................................................................................................. 21
3.5 Grounding ................................................................................................................... 23
3.6 Component land patterns ............................................................................................ 24
4 Example Reference Design........................................................................... 25
4.1 High-level layout concept ........................................................................................... 25
4.2 Stack-up and layer descriptions .................................................................................. 27
4.2.1 Layer 1 description............................................................................................ 27
4.2.2 Layer 2 description............................................................................................ 28
4.2.3 Layer 3 description............................................................................................ 30
4.2.4 Layer 4 description............................................................................................ 32
4.2.5 Layer 5 description............................................................................................ 32
4.2.6 Layer 6 description............................................................................................ 33
5 Specific Layout Guidelines........................................................................... 34
5.1 RF signals ................................................................................................................... 34
5.1.1 General RF guidelines ....................................................................................... 34
5.1.2 Clearing ground below RF traces and pads....................................................... 36
5.1.3 GPS circuits and signals .................................................................................... 36
5.1.4 Front-end circuits and signals............................................................................ 37
5.1.5 RFIC matching networks................................................................................... 38
5.2 LO-related circuits and signals ................................................................................... 40
5.2.1 LO signals (at UHF) .......................................................................................... 40
5.2.2 VCO tuning lines............................................................................................... 41
5.2.3 TCXO distribution............................................................................................. 42
5.3 Baseband Rx and Tx signals ....................................................................................... 43
5.4 Digital signal traces .................................................................................................... 44
5.4.1 PDM signals: TX_AGC_ADJ and TRK_LO_ADJ........................................... 44
5.4.2 SBI signals......................................................................................................... 44
5.4.3 Other digital signals........................................................................................... 45
5.5 DC power.................................................................................................................... 46
5.5.1 PA power supply distribution............................................................................ 46
5.5.2 Power supply traces routed under RFICs .......................................................... 47
6 Other Board-level Considerations ............................................................... 49
6.1 Radiated desensitization.............................................................................................. 49
6.1.1 Desensitization due to the CHIPx16 45th harmonic .......................................... 49
6.1.2 Desensitization due to the TCXO 46th harmonic............................................... 50
6.1.3 Desensitization due to LCD and camera interface ............................................ 53
6.2 GPS functions ............................................................................................................. 54
6.3 Thermal considerations............................................................................................... 54
7 Layout Checklist............................................................................................ 56 LZ能否下载下来，传这里呢 就是不好下载，所以问大家有没有看过这个资料，在google上也搜不到。
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