射頻鏈路指標預(yù)算

1、射頻鏈路指標預(yù)算射頻鏈路指標預(yù)算目錄中頻盤鏈路構(gòu)成中頻盤鏈路構(gòu)成OIP3OIP3與與NFNF計算公式計算公式發(fā)射通道鏈路預(yù)算發(fā)射通道鏈路預(yù)算反饋通道鏈路預(yù)算反饋通道鏈路預(yù)算接收通道鏈路預(yù)算接收通道鏈路預(yù)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靈敏度分析接收靈敏度分析阻塞與反混疊濾波器分析阻塞與反混疊濾波器分析互調(diào)分析互調(diào)分析半中頻雜散分析半中頻雜散分析LCLC濾波器設(shè)計濾波器設(shè)計濾波器帶寬要求濾波器帶寬要求中頻盤鏈路構(gòu)成OIP3與NF計算公式 以兩階系統(tǒng)為例：發(fā)射通道鏈路預(yù)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反饋通道鏈路預(yù)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接收通道鏈路預(yù)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-101010026374307-99PI-3310023374307-102BIF3205.240433.20931746636.31592-82pxv1220s-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基本公式系統(tǒng)ACPR = RF Power 熱噪聲 NF - 信號底噪 最大非線性產(chǎn)物接收靈敏度 = 熱噪聲 + NF + SNR 處理增益OIP3 = RF Power + IMD3/2，IMD3 = RF Power 最大非線性產(chǎn)物最大非線性產(chǎn)物 = RF Power 2*(OIP3 - RF Power )OIP3 = IIP3 + G，IIP3 = RF Power(Input) + IMD3/2(Input)接

7、收系統(tǒng)串聯(lián)IIP2 = 2*RF Power + Pr = RF Power + IMR2IMR2 = RF Power - PrACPR分析1.DAC1.DAC時鐘相噪對時鐘相噪對DACDAC輸出信號底噪的貢獻：輸出信號底噪的貢獻：-145 - 20lg(737.28M/140M) = -159.43dBm/Hz-145 - 20lg(737.28M/140M) = -159.43dBm/Hz2.DAC2.DAC輸出信號的總底噪：輸出信號的總底噪：-159.43 + (-158) = -155.58dBm/Hz-159.43 + (-158) = -155.58dBm/Hz3.3.84M3.

8、3.84M帶寬的擴頻增益：帶寬的擴頻增益：10lg3.84M = 65.84dB10lg3.84M = 65.84dB4.DAC4.DAC在發(fā)射通道輸出口的總噪聲：在發(fā)射通道輸出口的總噪聲：-155.58 + 65.84 + 10 = -79.74dBm/3.84MHz-155.58 + 65.84 + 10 = -79.74dBm/3.84MHz5.5.發(fā)射通道輸出口的總熱噪聲：發(fā)射通道輸出口的總熱噪聲：-174 + 65.84 + 10 + 18.86 = -79.3dBm/3.84MHz-174 + 65.84 + 10 + 18.86 = -79.3dBm/3.84MHz6.6.發(fā)射通

9、道輸出口的信號底噪：發(fā)射通道輸出口的信號底噪：-79.3+ (-79.74) = -76.5dBm/3.84MHz-79.3+ (-79.74) = -76.5dBm/3.84MHz7.7.發(fā)射通道輸出口的最大非線性產(chǎn)物：發(fā)射通道輸出口的最大非線性產(chǎn)物：-3.5 2-3.5 2* *(31.5+3.5) = -73.5dBm(31.5+3.5) = -73.5dBm8.8.發(fā)射信號的發(fā)射信號的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 dBm-35 + 10 + 50 -35 = -10 dBm2.2.共站時腔體濾波器所需抑制度：共站時腔體濾波器所需抑制度：-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.進入進入ADCADC的熱噪聲：的熱噪聲：-174 + 65.84 + 33.5 - 15.5 = -90.16dBm/3.84MHz-174 + 65.84 + 33.5 - 15.5 = -90.16dBm/3.84MHz2.2.進入進入ADCADC的最大非線性產(chǎn)物：的最大非線性產(chǎn)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.反饋信號進入反饋信號進入ADCADC后所能達到的最大后所能達到的最大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接收靈敏度分析1.WCDMA1.WCDMA靈敏度測試使用的是單載波靈敏度測試使用的是單載波3.84M3.84M帶寬。帶寬。2.2.處理增益：處理增益：10lg(3.84M/12.2k)= 2

15、5dB10lg(3.84M/12.2k)= 25dB3.4.5M3.4.5M的熱噪聲：的熱噪聲：-174 + 10lg3.84M = -108.16dBm/3.84MHz-174 + 10lg3.84M = -108.16dBm/3.84MHz4.4.接收靈敏度：接收靈敏度：-108.16 25 + 3.2 + 6 = -123.96 dBm/3.84M-108.16 25 + 3.2 + 6 = -123.96 dBm/3.84M( (協(xié)議要求低于協(xié)議要求低于-121dBm)-121dBm)RSSI analysisLOG or FMAGNITUDEKTB-174BW3840000BW GA

16、IN65.84331NF3.2KTB 3.84MBW-108.157KTB NF-104.957Process Gain25SNR6Receive Sensitivity-123.957阻塞與反混疊濾波器分析1.1.當(dāng)有大阻塞信號進入時，為了使當(dāng)有大阻塞信號進入時，為了使ADCADC不溢出，混不溢出，混頻器與小功率放大器有更好的線性表現(xiàn)，上行頻器與小功率放大器有更好的線性表現(xiàn)，上行DCADCA增益是需要衰減的。衰減后整個上行的噪聲系數(shù)為增益是需要衰減的。衰減后整個上行的噪聲系數(shù)為5.55.5。2.2.熱噪聲：熱噪聲：-174 + 10lg3.84M + 5.5= -102.66dBm/3.84

17、M-174 + 10lg3.84M + 5.5= -102.66dBm/3.84M3.3.除去熱噪后可接受的總噪聲：除去熱噪后可接受的總噪聲：-96 (-102.66) = -97.06dBm-96 (-102.66) = -97.06dBm4.4.帶內(nèi)反混疊濾波器所需要的抑制度：帶內(nèi)反混疊濾波器所需要的抑制度：-35 (-97.06)= 62.06dB-35 (-97.06)= 62.06dB5.5.考慮到上行通道的平坦度，以及阻塞大信號進入考慮到上行通道的平坦度，以及阻塞大信號進入上行通道后所引起的非線性效應(yīng)，需要再保留上行通道后所引起的非線性效應(yīng)，需要再保留3dB3dB。帶內(nèi)反混疊濾波器

18、所需要的抑制度：。帶內(nèi)反混疊濾波器所需要的抑制度：62.06 + 3 =65dB62.06 + 3 =65dB6.6.帶外阻塞信號為帶外阻塞信號為-15dBm-15dBm，所以對于帶外阻塞信號，所以對于帶外阻塞信號反混疊濾波器所需要的抑制度：反混疊濾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互調(diào)分析1.1.在天線口除去熱噪聲后最大可接受的噪聲：在天線口除去熱噪聲后最大可接受的噪聲：-97.06dBm-97.06dBm2.2.假設(shè)互調(diào)產(chǎn)物占假設(shè)互調(diào)產(chǎn)物占50%50%：-97.06 3 = -100.06dBm-97.06 3 = -100.06dBm3.3.輸入輸入IIP3IIP3：-48 +-48(-100.6)/2 = -21.9

20、7dBm-48 +-48(-100.6)/2 = -21.97dBm4.4.輸出輸出OIP3OIP3：-21.97 + 50 = 28.03dBm-21.97 + 50 = 28.03dBm 互調(diào)信號相對于靈敏度信號依然是大信號，所以上互調(diào)信號相對于靈敏度信號依然是大信號，所以上行通道也需要做適當(dāng)?shù)乃p，這樣可以降低上行通行通道也需要做適當(dāng)?shù)乃p，這樣可以降低上行通道道OIP3OIP3的要求，節(jié)約器件成本。的要求，節(jié)約器件成本。IP3 analysisLOG or FMAGNITUDEWanted SINGAL-115SNR6Process Gain25Acceptable MAX noise-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半中頻雜散分析1.1.半中頻雜散：半中頻雜散： 頻率為頻率為IF/2 + FloIF/2 + Flo，經(jīng)過混頻器下變頻以后會進入，經(jīng)過混頻器下變頻以后會進入中頻不會被混頻器以后的模擬濾波器與數(shù)字數(shù)字濾中頻不會被混頻器以后的模擬濾波器與數(shù)字數(shù)字濾波器濾除。波器濾除。