射频链路指标预算课件.ppt

1、射频链路指标预算射频链路指标预算目录中频盘链路构成中频盘链路构成OIP3OIP3与与NFNF计算公式计算公式发射通道链路预算发射通道链路预算反馈通道链路预算反馈通道链路预算接收通道链路预算接收通道链路预算基本公式基本公式ACPRACPR分析分析本振泄露分析本振泄露分析DPDDPD通道分析通道分析接收灵敏度分析接收灵敏度分析阻塞与反混叠滤波器分析阻塞与反混叠滤波器分析互调分析互调分析半中频杂散分析半中频杂散分析LCLC滤波器设计滤波器设计滤波器带宽要求滤波器带宽要求中频盘链路构成OIP3与NF计算公式 以两阶系统为例：发射通道链路预算 G=10dB，NF=18.9，OIP3=31.5，Pout=

2、-3.5PinTX-13.5DeviceGainNFIP3S GainS NFS IP3PoutLPF-11100-11100-14.5TRF37031112301223-13.5PI-55100-512.555428818-18.5RFFILTER-44100-913.5778651914-22.5PI-44100-1315.415986510-26.5BG18C15.54.5402.518.5176614225.34858-11HMC472-3335-0.518.5517219722.11891-14PI-33100-3.518.6188937319.11891-17BG18C15.54.

3、5401218.855325133.51415-1.5PI-221001018.8574106631.51415-3.5反馈通道链路预算 G=-15.5dB，NF=33.5，OIP3=33.8，Pout=0PinCP15.5DeviceGainNFIP3S GainS NFS IP3PoutHMC472-171735-171735-1.5HMC349-1149-181833.86479-2.5HMC485-9940-272724.73366-11.5LPF-11100-282823.73366-12.5PI-11100-292922.73366-13.5BIF3164.540-1333.536

4、.310542.5LPF00100-1333.536.310542.5PI-11100-1433.5100105635.310541.5ETC412-1.51.5100-15.533.530020533.810530接收通道链路预算 G=54.5dB，NF=3.21，OIP3=34.3PinRX-125DeviceGainNFIP3S GainS NFS IP3PoutLNA3033030330-95PI-22100283.00127290928-97HMC485-9940193.02515252418.96564-106LPF-11100183.03220093517.96564-107PI

5、-22100163.05218304315.96564-109BIF3205.240363.1752821634.51999-89HMC4720035363.1752821631.74307-89SAWFILTER-1010100263.18000564421.74307-99PI-33100233.18522311918.74307-102BIF3205.240433.20931746636.31592-82pxv1220s-33100403.20942092933.31592-85BIF3205.240603.20990030539.80218-65LPF-11100593.2099008

6、4238.80218-66PI-33100563.20990344135.80218-69ETC412-1.51.510054.53.2099055934.30218-70.5基本公式系统ACPR = RF Power 热噪声 NF - 信号底噪 最大非线性产物接收灵敏度 = 热噪声 + NF + SNR 处理增益OIP3 = RF Power + IMD3/2，IMD3 = RF Power 最大非线性产物最大非线性产物 = RF Power 2*(OIP3 - RF Power )OIP3 = IIP3 + G，IIP3 = RF Power(Input) + IMD3/2(Input)接

7、收系统串联IIP2 = 2*RF Power + Pr = RF Power + IMR2IMR2 = RF Power - PrACPR分析1.DAC1.DAC时钟相噪对时钟相噪对DACDAC输出信号底噪的贡献：输出信号底噪的贡献：-145 - 20lg(737.28M/140M) = -159.43dBm/Hz-145 - 20lg(737.28M/140M) = -159.43dBm/Hz2.DAC2.DAC输出信号的总底噪：输出信号的总底噪：-159.43 + (-158) = -155.58dBm/Hz-159.43 + (-158) = -155.58dBm/Hz3.3.84M3.

8、3.84M带宽的扩频增益：带宽的扩频增益：10lg3.84M = 65.84dB10lg3.84M = 65.84dB4.DAC4.DAC在发射通道输出口的总噪声：在发射通道输出口的总噪声：-155.58 + 65.84 + 10 = -79.74dBm/3.84MHz-155.58 + 65.84 + 10 = -79.74dBm/3.84MHz5.5.发射通道输出口的总热噪声：发射通道输出口的总热噪声：-174 + 65.84 + 10 + 18.86 = -79.3dBm/3.84MHz-174 + 65.84 + 10 + 18.86 = -79.3dBm/3.84MHz6.6.发射通

9、道输出口的信号底噪：发射通道输出口的信号底噪：-79.3+ (-79.74) = -76.5dBm/3.84MHz-79.3+ (-79.74) = -76.5dBm/3.84MHz7.7.发射通道输出口的最大非线性产物：发射通道输出口的最大非线性产物：-3.5 2-3.5 2* *(31.5+3.5) = -73.5dBm(31.5+3.5) = -73.5dBm8.8.发射信号的发射信号的ACPRACPR：-76.5 + (-73.5) (-3.5) = -68.2-76.5 + (-73.5) (-3.5) = -68.2ACPR analysisLOG or FMAGNITUDEKTB

10、-1743.98107E-18SAMPLE CLK (M)737.28BW3840000IF (M)140CLK NOISE -145DAC NOISE-1581.58489E-16CLK TO DAC NOISE-159.431.14023E-16DAC OUTPUT NOISE-155.5832.76493E-16BW GAIN65.84331DAC NOISE FLOOR-89.73981.06173E-09CHANNEL NF18.86CHANNEL GAIN10CHANNEL OIP331.5SIGNAL POWER-3.5SIGNAL Noise-79.73981.06173E-0

11、8KTB Noise-79.29671.17579E-08SIGNAL NF-76.50232.23753E-08CHANNEL OIP3 TO ACPR-70MAX P3rd-73.54.46684E-08Total CHANNEL Noise-71.73646.70436E-08CHANNEL MAX ACPR-68.2364本振泄露分析1.1.功放口的本振泄露：功放口的本振泄露：-35 + 10 + 50 -35 = -10 -35 + 10 + 50 -35 = -10 dBmdBm2.2.共站时腔体滤波器所需抑制度：共站时腔体滤波器所需抑制度：-10 (-86) = 76dB-10

12、(-86) = 76dBLO leakageLOG or FIQ leakage -35TX channel gain10PA gain50RF filter35PA leakage-10coexist requirement-86Cavity filter76DPD通道分析1.1.进入进入ADCADC的热噪声：的热噪声：-174 + 65.84 + 33.5 - 15.5 = -90.16dBm/3.84MHz-174 + 65.84 + 33.5 - 15.5 = -90.16dBm/3.84MHz2.2.进入进入ADCADC的最大非线性产物：的最大非线性产物：0 20 2* *(33.8

13、 + 0) = -67.6dBm(33.8 + 0) = -67.6dBm3.ADC3.ADC的底噪：的底噪：4 66 10lg (92.16M/3.84M) = -4 66 10lg (92.16M/3.84M) = -75.8dBm/3.84MHz75.8dBm/3.84MHz4.4.反馈信号进入反馈信号进入ADCADC后所能达到的最大后所能达到的最大ACPRACPR： -90.16 + (-67.6) + (-75.8) 0 = -66.97 -90.16 + (-67.6) + (-75.8) 0 = -66.97DPD analysisLOG or FMAGNITUDECHANNEL

14、 NF33.5CHANNEL GAIN-15.5CHANNEL OIP333.8SIGNAL POWER0KTB NF-90.1567NF TO ACPR-90.15679.64564E-10OIP3 TO ACPR-67.61.7378E-07ADC FS Power4ADC SNR66ADC NF-75.80212.62899E-08CHANNEL MAX ACPR-66.96732.01035E-07接收灵敏度分析1.WCDMA1.WCDMA灵敏度测试使用的是单载波灵敏度测试使用的是单载波3.84M3.84M带宽。带宽。2.2.处理增益：处理增益：10lg(3.84M/12.2k)= 2

15、5dB10lg(3.84M/12.2k)= 25dB3.4.5M3.4.5M的热噪声：的热噪声：-174 + 10lg3.84M = -108.16dBm/3.84MHz-174 + 10lg3.84M = -108.16dBm/3.84MHz4.4.接收灵敏度：接收灵敏度：-108.16 25 + 3.2 + 6 = -123.96 -108.16 25 + 3.2 + 6 = -123.96 dBmdBm/3.84M/3.84M( (协议要求低于协议要求低于-121dBm)-121dBm)RSSI analysisLOG or FMAGNITUDEKTB-174BW3840000BW GA

16、IN65.84331NF3.2KTB 3.84MBW-108.157KTB NF-104.957Process Gain25SNR6Receive Sensitivity-123.957阻塞与反混叠滤波器分析1.1.当有大阻塞信号进入时，为了使当有大阻塞信号进入时，为了使ADCADC不溢出，混不溢出，混频器与小功率放大器有更好的线性表现，上行频器与小功率放大器有更好的线性表现，上行DCADCA增益是需要衰减的。衰减后整个上行的噪声系数为增益是需要衰减的。衰减后整个上行的噪声系数为5.55.5。2.2.热噪声：热噪声：-174 + 10lg3.84M + 5.5= -102.66dBm/3.84

17、M-174 + 10lg3.84M + 5.5= -102.66dBm/3.84M3.3.除去热噪后可接受的总噪声：除去热噪后可接受的总噪声：-96 (-102.66) = -97.06dBm-96 (-102.66) = -97.06dBm4.4.带内反混叠滤波器所需要的抑制度：带内反混叠滤波器所需要的抑制度：-35 (-97.06)= 62.06dB-35 (-97.06)= 62.06dB5.5.考虑到上行通道的平坦度，以及阻塞大信号进入考虑到上行通道的平坦度，以及阻塞大信号进入上行通道后所引起的非线性效应，需要再保留上行通道后所引起的非线性效应，需要再保留3dB3dB。带内。带内反混叠

18、滤波器所需要的抑制度：反混叠滤波器所需要的抑制度：62.06 + 3 =65dB62.06 + 3 =65dB6.6.带外阻塞信号为带外阻塞信号为-15dBm-15dBm，所以对于带外阻塞信号，所以对于带外阻塞信号反混叠滤波器所需要的抑制度：反混叠滤波器所需要的抑制度：-15 - -15 - （-97.06-97.06）+ 3 = 85.06dB+ 3 = 85.06dBBlock analysisLOG or FMAGNITUDEBLOCK SIGNAL-353GPP=-40dBWanted SINGAL-115SNR6Process Gain25Acceptable MAX noise-9

19、62.51189E-10Channel NF5.5KTB -1743.84MBW KTB with NF-102.6575.42414E-11Total Noise-97.05651.96947E-10Filter Restriction62.0565互调分析1.1.在天线口除去热噪声后最大可接受的噪声：在天线口除去热噪声后最大可接受的噪声：-97.06dBm-97.06dBm2.2.假设互调产物占假设互调产物占50%50%：-97.06 3 = -100.06dBm-97.06 3 = -100.06dBm3.3.输入输入IIP3IIP3：-48 +-48(-100.6)/2 = -21.9

20、7dBm-48 +-48(-100.6)/2 = -21.97dBm4.4.输出输出OIP3OIP3：-21.97 + 50 = 28.03dBm-21.97 + 50 = 28.03dBm 互调信号相对于灵敏度信号依然是大信号，所以上互调信号相对于灵敏度信号依然是大信号，所以上行通道也需要做适当的衰减，这样可以降低上行通行通道也需要做适当的衰减，这样可以降低上行通道道OIP3OIP3的要求，节约器件成本。的要求，节约器件成本。IP3 analysisLOG or FMAGNITUDEWanted SINGAL-115SNR6Process Gain25Acceptable MAX noise

21、-962.51189E-10KTB IN 3.84M BW-102.6575.42414E-11MAX Noise except KTB-97.05651.96947E-10IM product-100.057Assume 50%CHANNEL GAIN503GPP -48dBm-48IIP3-21.9717OIP328.02825半中频杂散分析1.1.半中频杂散：半中频杂散： 频率为频率为IF/2 + FloIF/2 + Flo，经过混频器下变频以后会进入，经过混频器下变频以后会进入中频不会被混频器以后的模拟滤波器与数字数字滤中频不会被混频器以后的模拟滤波器与数字数字滤波器滤除。波器滤除。2

22、.2.在天线口除去热噪声后最大可接受的噪声：在天线口除去热噪声后最大可接受的噪声：-97.06dBm-97.06dBm3.3.针对半中频杂散所需的抑制度：针对半中频杂散所需的抑制度：16 - 16 - （-97.06-97.06）= 113.06= 113.064.4.换算成串联换算成串联IIP2IIP2：16 + 113.06 = 129.06dBm 16 + 113.06 = 129.06dBm 5.5.系统串联系统串联IIP2 = IIP2 = 混频器混频器IIP2 IIP2 混频器前总增混频器前总增益益 + 2 + 2* *滤波器抑制度滤波器抑制度6.6.对应的腔体滤波器抑制度要求：对

23、应的腔体滤波器抑制度要求：(129.06 + 28 39)/2 = 59.03dB(129.06 + 28 39)/2 = 59.03dBHalf IF spur analysisLOG or FMAGNITUDEInput Half IF spur16MAX Noise except KTB-97.0565IMR2113.0565Serial IIP2129.0565Mixture IIP239datasheetGain before Mixture28Require Filter IMR259.02825LC滤波器设计LC滤波器设计LC滤波器设计LC滤波器设计滤波器带宽要求 DPD算法要求能够采集到5阶互调产物 发射通道的介质滤波器的带宽= 5*信号带宽 + 协议规定的频率范围 - 信号带宽 反馈通道的带通滤波器的带宽= 5*信号带宽附录Thank you for listening