手机EMC测试及设计介绍

1、Page 1手机手机EMC测试与设计介绍测试与设计介绍Page 2手机手机EMCEMC测试项目测试项目1手机手机EMCEMC测试方法及问题分析测试方法及问题分析手机手机EMCEMC设计常用器件设计常用器件总结总结2345EMCEMC概念概念Page 31. EMC1. EMC概念概念EMC: electromagnetic compatibility电磁兼容性电磁兼容性EMI: electromagnetic interference电磁干扰电磁干扰EMS: Electromagnetic Susceptibility电磁敏感度电磁敏感度Page 41. EMC1. EMC概念概念: : 为什

2、么要进行为什么要进行EMCEMC测试？测试？防止手机被干扰。防止手机被干扰。防止手机干扰其他电子设备。防止手机干扰其他电子设备。手机上市需要手机上市需要CTACTA认证，认证，CTACTA认证中具有对认证中具有对EMCEMC的的明确要求。明确要求。Page 52.2.手机手机EMCEMC测试项目测试项目CI CI Immunity to conducted RF disturbances射频场感应的传导骚扰抗扰度射频场感应的传导骚扰抗扰度RI RI Immunity to radiated RF disturbances辐射骚扰抗扰度辐射骚扰抗扰度RE RE Radiated emission

3、s辐射骚扰辐射骚扰RSE RSE Radiated spurious emissions辐射杂散骚扰辐射杂散骚扰CE CE Conducted emissions on AC/DC ports and signal lines传导连续骚扰传导连续骚扰AC voltage dips and interruption(电压暂降和短时中断抗扰度电压暂降和短时中断抗扰度)Electrical fast transients电快速瞬变脉冲群抗扰度电快速瞬变脉冲群抗扰度AC surges(浪涌（冲击）抗扰度浪涌（冲击）抗扰度)Page 62.2.手机手机EMCEMC测试项目测试项目NOKIA EMCNOK

4、IA EMC测试项测试项JTRc2.1.1AC voltage dips and interruption(电压暂降和短时中断抗扰度)TD/GSMJTRc2.1.2Electrical fast transients,common and differential mode电快速瞬变脉冲群抗扰度TD/GSMJTRc2.1.3AC surges,common and differential mode(浪涌（冲击）抗扰度)TD/GSMFail / Pass LimitProduct shall work with normal performance when connected to AC c

5、harger in case of voltage deviations by +/-20% of Unomwith the following parameters:AC voltage deviationNo relation with FrequencyFail / Pass LimitProduct shall work with normal performance when connected to AC charger during AC supply networkvoltage variation by +/-20 % of Unom within min. 10 minut

6、esAC voltage variationNo relation with FrequencyGuanyu EMC test casePage 72.2.手机手机EMCEMC测试项目测试项目JTRc2.2.1Automotive environment “Start pulse”No relation with FrequencyJTRc2.2.2Automotive environment “Load dump”No relation with FrequencyJTRc2.2.3Automotive environment “Field decay”No relation with Fr

7、equencyJTRc2.2.4Automotive environment “DC supply immunity”No relation with FrequencyJTRc2.2.5Automotive environment “Transients”No relation with FrequencyJTRc2.2.6Automotive environment “Micro interruptions”No relation with FrequencyJTRc2.2.7Automotive environment “Transients burst on DC input/outp

8、ut linesNo relation with FrequencyJTRc2.2.8Automotive environment “Transients burst on I/O lines”No relation with FrequencyThe product shall withstand in case of overvoltage without damage: i) +18V for 1 hourii) +24 V for 15 min iii) +27V for 1 min Ri 0.1 OhmAutomotive environment “Over voltage”No r

9、elation with Frequency The product shall fulfill following requirements in case of dc supply voltage variation:T = +55C Uo min/max: for 12 V equipment i) 1624 V intermittent function II ii) 10.816 V normal performanceiii) 7.210.8 V reduced performance iv) 07.2 Automotive environment “DC voltage vari

10、ation”No relation with FrequencyThe product shall withstand in case of reverse polarity without damage:-16V (12V systems) -32V (24V systems) duration: 15 minAutomotive environment “Reverse polarity”No relation with FrequencyPage 82.2.手机手机EMCEMC测试项目测试项目JTRc2.3.1Immunity to radiated RF disturbances辐射骚

11、扰抗扰度TD/GSMJTRc2.4.1Immunity to conducted RF disturbances射频场感应的传导骚扰抗扰度TD/GSMJTRc2.5.1 SPR Limits: 2, 4, 8 kV contact discharge 2, 4, 8, 10, 15* kV air discharge15 kV: no damage or loss of stored dataElectrostatic discharge静电放电抗扰度TD/GSMJTRc2.6.1.1JTR limit = CTA limit 6dBmCTA limit: 30MHz to 230MHz (3

12、m): 40 dBuV/m230MHz to 1GHz (3m): 47 dBuV/mRadiated emissions from product combinations, idle mode辐射骚扰TD/GSMJTRc2.6.2.1JTR limit= CTA limit 6dBmCTA limitTX: 36dBm 30MHz 1GHz, -30dBm 1GHz 6GHzRX: 57dBm 30MHz 1GHz, -47dBm 1GHz 6GHzTD-SCDMA system:The radiated spurious emissions from the transceiver of

13、 the mobile phone shall be at least 6dB below the official limit. The product shall fulfill this requirement together with the officially supported accessories. The worst-case conditions shall be searched. Incorperated functionality (e.g. camera or MP3) shall fulfill this requirement also.Radiated s

14、purious emissions from transceiver, Tx & Rx辐射杂散骚扰TD/GSMJTRc2.8.1 SPR limit= CTA limit 6dBmConducted emissions on AC/DC ports and signal lines传导连续骚扰TD/GSMPeak limit=74dBuV/m Avg.Limit=54dBuV/mSpurious Emission(Bluetooth)Cell7W, PCS2WEquivalent Isotropically Radiated Power(EIRP)GSMPage 93.3.手机手机EM

15、CEMC测试方法及问题分析测试方法及问题分析Guanyu; Tahiti; T702T; T802T.Guanyu; Tahiti; T702T; T802T.Page 103.1. CI 测试系统测试系统Page 113.1. CI 测试系统测试系统Page 123.1. CI 3.1. CI 测试系统测试系统CDNCDN：交直流主电源去藕：交直流主电源去藕/ /耦合网络耦合网络ClampClamp：电流钳：电流钳CDN框图框图ClampPage 13CI uplink uplink测试测试Page 14CI uplink uplink测试流程测试流程首先由仿真嘴发出一个参考声音首先由仿真嘴

16、发出一个参考声音0dB0dB，被测手机接收该声音，并通过无线的方，被测手机接收该声音，并通过无线的方式发给式发给CMUCMU，CMUCMU把接收到的信号还原成语音信号送给把接收到的信号还原成语音信号送给UPLUPL分析，得出一个参考分析，得出一个参考响度值。响度值。移除参考声音，通过移除参考声音，通过CDNCDN或或ClampClamp加入干扰，再由加入干扰，再由CMUCMU接收手机发送过来的信号，接收手机发送过来的信号，还原成语音信号送给还原成语音信号送给UPLUPL，UPLUPL分析加入不同频率干扰后语音信号的响度。同之分析加入不同频率干扰后语音信号的响度。同之前的参考响度比较得出前的参考

17、响度比较得出dBdB值。值。Page 15CI downlink downlink测试测试Page 16CI downlink downlink测试测试首先由仿真嘴发出一个参考声音，由首先由仿真嘴发出一个参考声音，由UPL接收分析，得出一个参考响度值。接收分析，得出一个参考响度值。移除参考声音，通过移除参考声音，通过CDN或或Clamp加入干扰，由仿真耳接收手机电声元件发出加入干扰，由仿真耳接收手机电声元件发出的声音送给的声音送给UPL进行分析，得出手机在加入不同频率干扰后语音信号的响度。同进行分析，得出手机在加入不同频率干扰后语音信号的响度。同之前的参考响度比较得出之前的参考响度比较得出dB

18、值。值。Page 17CI 5CI 5种测试模式种测试模式CICI测试分为测试分为5 5种测试模式，每种模式都包括种测试模式，每种模式都包括uplinkuplink和和downlinkdownlink。测试模式干扰方式干扰设备HPCDNChargerHSCDNChargerHFCDNChargerHSClampChargerHSClampHandsetHP: Hand PhoneHP: Hand PhoneHS: HeadsetHS: HeadsetHP: Hand FreeHP: Hand FreePage 18CI 测试要求及判定标准测试要求及判定标准Interference signal

19、: 150 kHz 80 MHz, 1kHz AM 80%, min 6Vrms Judgment StandardNOKIA standard: (Refer to EMC testing quidelines for ODM suppliers of mobile terminals V21.0)audio response in uplink 40dB at 1kHzaudio response in downlink 35dB at 1kHzPage 193.1 CI3.1 CI问题问题1 1 上行参考值上行参考值上行参考值低，上行音频响度正常。自动增益控制的实现机制有问题。上行参考值

20、低，上行音频响度正常。自动增益控制的实现机制有问题。Page 203.1 CI3.1 CI问题问题2 2 固有噪声固有噪声上行上行TDMA noise 严重，导致音频底噪声超标。严重，导致音频底噪声超标。Page 21Guanyu CI uplink uplink 问题分析问题分析CI Up-link failed in all test case, and the waveform is very flat. Page 22Guanyu CI uplink debug - HP uplink debug - HPPage 23Guanyu CI uplink debug - HP uplin

21、k debug - HPPage 24Guanyu CI uplink debug - HP uplink debug - HPPage 25Guanyu CI uplink debug - HP uplink debug - HP修改后的测试结果Page 26Guanyu CI uplink uplink debug - HFdebug - HF3.1 CI3.1 CI问题问题3 3 SPKSPK影响影响MICMICPage 27Guanyu CI uplink debug - HF uplink debug - HF修改后的测试结果Page 28Guanyu CI downlink dow

22、nlink问题问题3.1 CI3.1 CI问题问题4 4 耳机下行耳机下行Page 29Guanyu CI downlink debug - HS downlink debug - HSChange C1153 and C1159 from 1nF to 22nFPage 30Guanyu CI downlink debug - HS downlink debug - HS修改后的测试结果Page 313.1 CI3.1 CI问题问题5 5 耳机上行耳机上行Page 323.1 CI3.1 CI问题问题5 5 耳机上行耳机上行Change C939, C941 from 39pF to 10n

23、F.Page 333.2. RI 测试系统测试系统Page 34RI uplink uplink测试测试Page 35RI uplink uplink测试测试首先由仿真嘴发出一个参考声音首先由仿真嘴发出一个参考声音0dB，被测手机接收该声音，并通过无线的，被测手机接收该声音，并通过无线的方式发给方式发给CMU，CMU把接收到的信号还原成语音信号送给把接收到的信号还原成语音信号送给UPL分析，得出分析，得出一个参考响度值。一个参考响度值。移除参考声音，通过天线加入干扰，再由移除参考声音，通过天线加入干扰，再由CMU接收手机发送过来的信号，接收手机发送过来的信号，还原成语音信号送给还原成语音信号送

24、给UPL，UPL分析加入不同频率干扰后语音信号的响度。分析加入不同频率干扰后语音信号的响度。同之前的参考响度比较得出同之前的参考响度比较得出dB值。值。Page 36RI downlink downlink测试测试Page 37RI downlink downlink测试测试首先由仿真嘴发出一个参考声音，由首先由仿真嘴发出一个参考声音，由UPL接收分析，得出一个参考响度接收分析，得出一个参考响度值。值。移除参考声音，通过天线加入干扰，由仿真耳接收手机电声元件发出的移除参考声音，通过天线加入干扰，由仿真耳接收手机电声元件发出的声音送给声音送给UPL进行分析，得出手机在加入不同频率干扰后语音信号的

25、响进行分析，得出手机在加入不同频率干扰后语音信号的响度。同之前的参考响度比较得出度。同之前的参考响度比较得出dB值。值。Page 38RI 测试模式测试模式RI RI 测试（包括测试（包括uplinkuplink和和downlinkdownlink）分为）分为3 3种测试模式，每种模式又分为种测试模式，每种模式又分为8 8个角度。个角度。3 3种模式：种模式：Hand phone, Hand Free Hand phone, Hand Free 和和 HeadsetHeadset。8 8种角度：种角度：0 0度垂直，度垂直，0 0度水平度水平, 9, 90度垂直，度垂直，90度水平度水平, 1

26、80度垂直，度垂直，180度水平度水平, 270度垂直，度垂直，270度水平。度水平。右图为可旋转的测试架：右图为可旋转的测试架：被测手机被测手机充电器充电器Page 39RI 测试要求及判定标准测试要求及判定标准Judgment StandardNOKIA standard: (Refer to EMC testing quidelines for ODM suppliers of mobile terminals V21.0)audio response in uplink 40dB at 1kHzaudio response in downlink 35dB at 1kHzInterfe

27、rence signal: 80 - 3000 MHz*, 1kHz AM 80%, min 6 V/mTurn table positions: 0, 90, 180, 270 degreeAntenna polarization: vertical and horizontalProduct position: vertical and horizontalPage 403.33.3 RERE测试测试Frequency MHzLevel dBmTransd dBLimit dBmMargin dBHeight cmAzimuth degPolarisationElevation deg34

28、.44000023.00-17.6040.0017.00170.068.00VERTICAL0.0042.24000030.30-21.9040.009.70170.014.00HORIZONTAL0.00dbV/mPage 41RERE测试测试GSM900, 1800, 1900, TD2010;Call mode, Idle mode;Slide open, slide close;Page 42RERE问题问题1 1：Page 43RERE问题问题1 1：Page 44RERE问题问题2 2：01 02 03 04 05 06 0L e v e l d B礦 / m3 0 M5 0 M7

29、 0 M1 0 0 M2 0 0 M3 0 0 M5 0 0 M7 0 0 M1 GF r e q u e n c y Hz xxxxxxx MES EN DCS Ab s _ f i n QP MES EN DCS Ab s _ p r e PK L I M EN5 5 0 2 2 B QP Page 453.4. RSE dbV/mPage 463.4. RSEPage 47GSM900 traffic mode. Failed at 2nd harmonic.Frequency is 1.80448GHz, margin is -5.8dB.Test at BYD ERI Lab.T70

30、2T RSE issue analyzing 3.4. RSE问题问题1Page 48RSETraffic_GSM900_30M_6GIMEI:869971000007600_v230.00M100.00M1.00G6.00GFrequency (Hz)-100-90-80-70-60-50-40-30-20-100102030ERP (dBm)EUT - Test Site - Start of test - RSE ResultLimitGSM900 traffic mode. Failed at 2nd harmonic.Margin is 0dB.Test at TMC RSE Lab

31、.2.T702T RSE issue analyzing Page 49Cover the shielding with sheet copper.Remove the unused main antenna spring, and cut off the ground.2.T702T RSE issue analyzing Page 50Cover the LCD FPC with sheet copper.Cover the LCD FPC with sheet copper.2.T702T RSE issue analyzing Page 51Remove the TVS diodes

32、for the HOME key.Remove the keypad backlight FPC springs.Cut off the HOME key connection.2.T702T RSE issue analyzing Page 52RSETraffic_GSM900_30M_6GIMEI:352099001761480Lenovo30.00M100.00M1.00G6.00GFrequency (Hz)-100-90-80-70-60-50-40-30-20-100102030ERP (dBm)EUT - Test Site - Start of test - RSE Resu

33、ltLimitOnly cutting off the HOME key connection has obvious improvement.For GSM900 traffic mode, pulse at 2nd harmonic. Margin is 7dB.2.T702T RSE issue analyzing Page 53Cut off bottom half of the HOME key pad and key DOME.Remove or not remove the TVS diodes for the HOME key.3.T702T RSE issue solutio

34、nScenario 1: Cut off HOME key.Page 54RSETraffic_GSM900_30M_6GIMEI:35209900176148030.00M100.00M1.00G6.00GFrequency (Hz)-100-90-80-70-60-50-40-30-20-100102030ERP (dBm)EUT - Test Site - FACStart of test - 2011-07-28RSE ResultLimitCut off HOME key and DOME has obvious improvement.With TVS diodes has 8dB

35、 margin.Without TVS diodes has 6.6dB margin.3.T702T RSE issue solutionPage 55Replace the TVS diodes to two 82pF capacitors.3.T702T RSE issue solutionScenario 2: Replace TVS to capacitor.Page 56RSETraffic_GSM900_30M_6GIMEI:352099001761480_V330.00M100.00M1.00G6.00GFrequency (Hz)-100-90-80-70-60-50-40-

36、30-20-100102030ERP (dBm)EUT - Test Site - FACStart of test - 2011-07-28RSE ResultLimitChanging capacitor has obvious improvement.Margin is 8dB.3.T702T RSE issue solutionPage 57SW change the HOME key operation mode from scan to GPIO.Change the TVS diode to 18pF capacitor or not.Remove D1112 and conne

37、ct MKIN1 to Ground.3.T702T RSE issue solutionScenario 3: Change HOME key Operation mode.Page 58RSETraffic_GSM900_30M_6GIMEI:86997100000696030.00M100.00M1.00G6.00GFrequency (Hz)-100-90-80-70-60-50-40-30-20-100102030ERP (dBm)EUT - Test Site - FACStart of test - 2011-07-28RSE ResultLimitChange HOME key

38、 operation mode has obvious improvement.With TVS diode has 8dB margin.TVS change to capacitor has 7dB margin.3.T702T RSE issue solutionPage 59Conclusion: Below three scenarios all have obvious improvement for RSE issue.Scenario 1: Cut off HOME key.Scenario 2: Replace TVS to capacitor.Scenario 3: Cha

39、nge HOME key Operation mode.Scenario 3 has minimum changes. So this scenario can be used for CTA samples rework.We can change the schematics and PCB layout according to these three scenarios.Change to HOME key operation mode from scan to GPIO.Add a inductor at HOME key signal in series.a. Decrease t

40、he HOME key footprint and move the footprint away from the main antenna keep-out area as far as possible.3.T702T RSE issue solutionPage 60This RSE issue is caused by the HOME key in main antenna area. Antenna area especially the bottom area must be keep out clearly. 4.T702T RSE issue lessons learntM

41、ain antenna keep-out areaHOME key footprint Page 61RSERSE问题问题2 2：Page 62RSERSE问题问题2 2：-65-60-50-40-30-25Level dBm6G7G8G9G10G11G12.75GFrequency HzMES 0507-6_pre LIM 30-36 RE02 Broadband LimitPage 634.5 AC和CEPage 644.4.手机手机EMCEMC设计常用器件设计常用器件4.14.1 电容电容4.24.2 磁珠磁珠4.34.3 TVSTVS4.44.4 压敏电阻压敏电阻4.54.5 EMI

42、filterEMI filter4.6 4.6 共模扼流圈共模扼流圈Page 654.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容电容在电路中电容在电路中起到滤波作用。起到滤波作用。电容器的容抗与频率成反比，正是利用这一特性，将电容并联在信号线与地线之间起到对高频噪声的旁路作用。如何选择电如何选择电容？容？Page 664.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容然而，在实际工程中，很多人发现这种方法并不能起到预期滤除噪声的效果，面对顽固的电磁噪声束手无策。理想电容的特性。理想电容的特性。频率频率阻抗阻抗Page 674.1.4.1.手机手机

43、EMCEMC设计常用器件：电容设计常用器件：电容实际电容的特性。实际电容的特性。实际电容器的电路模型由等效电感（ESL）、电容和等效电阻（ESR）构成的串联网络。在谐振点以上，由于电容的阻抗增加，因此对高频噪声的旁路作用减弱，甚至消失。频率频率阻抗阻抗ESRESRPage 684.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容电容的谐振频率由ESL和C共同决定，电容值或电感值越大，则谐振频率越低，也就是电容的高频滤波效果越差。电容引线越长，则电感越大，电容的谐振频率越低。Page 694.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容电容越大，谐振点

44、越低。许多人认为电容器的容值越大，滤波效果越好，这是一种误解。电容越大对低频干扰的旁路效果虽然好，但是由于电容在较低的频率发生了谐振，阻抗开始随频率的升高而增加，因此对高频噪声的旁路效果变差。电容值自谐振频率（MHz）电容值自谐振频率（MHz）1m F1.7820 pF38.50.1m F4680 pF42.50.01m F12.6560 pF453300pF19.3470 pF491800 pF25.5390 pF541100pF33330 pF60Page 704.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容尽管从滤除高频噪声的角度看，电容的谐振是不希望的，但是电容

45、的谐振并不是总是有害的。当要滤除的噪声频率确定时，可以通过调整电容的容量，使谐振点刚好落在骚扰频率上。频率频率阻抗阻抗干扰信干扰信号频率号频率Page 714.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容由于电容器中的介质参数受到温度变化的影响，因此电容器的电容值也随着温度变化。常用电容器有超稳定型：COG或NPO，稳定型：X7R，和通用型：Y5V或Z5U三种Page 724.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容COG电容器的容量几乎随温度没有变化，X7R电容器的容量在额定工作温度范围变化12%以下，Y5V电容器的容量在额定工作温度范围内

46、变化70%以上。这些特性是必须注意的，否则会出现滤波器在高温或低温时性能变化而导致设备产生电磁兼容问题。X7RX7RPage 734.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容COG介质虽然稳定，但介质常数较低，一般在10100，因此当体积较小时，容量较小。X7R的介质常数高得多，为2000 4000，因此较小的体积能产生较大的电容，Y5V的介质常数最高，为5000 25000。许多人在选用电容器时，片面追求电容器的体积小，这种电容器的介质虽然具有较高的介质常数，但温度稳定性很差，这会导致设备的温度特性变差。这在选用电容器时要特别注意。Page 744.1.4.1.手

47、机手机EMCEMC设计常用器件：电容设计常用器件：电容X7R电容器在额定电压状态下，其容量降为原始值的70%，而Y5V电容器的容量降为原始值的30%！了解了这个特性，在选用电容时要在电压或电容量上留出余量，否则在额定工作电压状态下，滤波器会达不到预期的效果。Page 754.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容穿心电容穿心电容在实际工程中，要滤除的电磁噪声频率往往高达数百MHz，甚至超过1GHz。对这样高频的电磁噪声必须使用穿心电容才能有效地滤除。普通电容之所以不能有效地滤除高频噪声，原因是电容引线电感造成电容谐振，对高频信号呈现较大的阻抗，削弱了对高频信号的旁

48、路作用。穿心电容，穿心电容， 极低的极低的ESR,ESLESR,ESL。Page 764.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容穿心电容穿心电容Page 774.1.4.1.手机手机EMCEMC设计常用器件：电容设计常用器件：电容穿心电容：较高的谐振频率，和极低的阻抗。穿心电容：较高的谐振频率，和极低的阻抗。Page 784.2.4.2.手机手机EMCEMC设计常用器件：磁珠设计常用器件：磁珠铁氧体材料是铁镁合金或铁镍合金，这种材料具有很高的导磁率。铁氧体材料通常在高频情况下应用，因为在低频时他们主要程电感特性，使得线上的损耗很小。在高频情况下，他们主要呈电抗特性比并且随频率改变。实际上，实际上，铁氧体较好的等效于电阻以及电感的并联，铁氧体较好的等效于电阻以及电感的并联，低频下电阻被电感短路，高频下电感阻抗变得相当高，以至于电流全部通过电阻