The document details various cases and calculations related to receiver performance metrics like noise figure (NF), gain, and sensitivity for different communication technologies, including GSM, CDMA, WCDMA, and LTE. It includes conditional cases for optimized output power and offers practical design references for high-pass filters. Performance tables summarize NF and sensitivity outcomes in various configurations, highlighting differences with and without external low-noise amplifiers (LNA).
代入理論公式太麻煩, 看能不能省去甚麼…
我們發現, LNA後方Stage會因分母有LNA的Gain,其值會變很小因此省略計算
10
1.26 1 1.22 1 2.51 1
2 3.08
0.5 0.5 0.79 0.5 0.79 31.62
10log (3.08) 4.88 [dB].
total
total
F
F
10
1.22 1 2 1 1.22 1 2.51 1
1.26 1.54
0.79 0.79 31.62 0.79 31.62 0.5 0.79 31.62 0.5 31.62
10log (1.54) 1.88 [dB].
total
total
F
F
做個table比較一下
NF 理論 NF 化簡
w/o eLNA 5.04 dB 4.88 dB
w/ eLNA 2.02 dB 1.88 dB
23.
化簡公式還要除, 還是覺得有點麻煩…看能不能更直觀 !!
直接將LNAinput Stage的NF總和 [dB], 與從天線下來遇到的第一顆LNA自身的NF [dB], 兩個相加
NFtot [dB] = LNA pre-loss [dB] + LNA NF [dB]
再做個table比較一下
NF 理論 NF 化簡 NF 直觀
w/o eLNA 5.04 dB 4.88 dB 4.85 dB
w/ eLNA 2.02 dB 1.88 dB 1.85 dB
w/o eLNA
w/ eLNA
差不多, 計算方便, 又直觀
But 與理論有些微誤差.
24.
LTE B2 FEASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.4 0.5 4.72 2.3 9 -1 -98.44
Max 1.62 0.83 3.5 0.4 0.8 7.15 3 9 -1 -95.31
For SXMX
LNA都先給他thru (w/o eLNA), 計算sensitivity
WCDMA B2 FE ASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.4 0.5 4.72 2.3 3.84 -9.5 -110.64
Max 1.62 0.83 3.5 0.4 0.8 7.15 3 3.84 -9.5 -107.51
BC1 FE ASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.4 0.5 4.72 2.3 1.23 -2 -108.08
Max 1.62 0.83 3.5 0.4 0.8 7.15 3 1.23 -2 -104.95
For SXMX
掛LNA (w/ eLNA), 計算sensitivity
由上頁知, NFtot [dB] = LNA pre-loss [dB] + LNA NF [dB]
Datasheet Infineon B2 LNA NF = 0.6-1.2, 再來我們忽略 RxSAW 與 DPDT 的NF.
LTE B2 FE ASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.6 0.5 4.92 2.3 9 -1 -98.24
Max 1.62 0.83 3.5 1.2 0.8 7.95 3 9 -1 -94.51
WCDMA B2 FE ASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.6 0.5 4.92 2.3 3.84 -9.5 -110.44
Max 1.62 0.83 3.5 1.2 0.8 7.95 3 3.84 -9.5 -106.71
BC1 FE ASM Duplexer LNA Rx SAW DPDT Trace loss Loss before WTR Rx NF Rx BW CN Sensitivity
Typ 1.24 0.68 1.9 0.6 0.5 4.92 2.3 1.23 -2 -107.88
Max 1.62 0.83 3.5 1.2 0.8 7.95 3 1.23 -2 -104.15
所以LNA掛WTR附近是沒有作用的.
25.
Type FEL +ASM + Dup Trace eLNA Trace + RxSAW iLNA
Stage Stage1 Stage2 Stage3 Stage4 Stage5
NF [dB] 5.95 0.8 1.2 0.4 3
Gain [dB] -5.95 -0.8 14.3 -0.4 35.12
NF 3.94 1.2 1.32 1.1 2
Gain 0.25 0.83 26.9 0.91 3250.87
那我們現在來計算一下LTE B2的NF
And loss use max value to calculate
B2 FE ASM Duplexer
Typ 1.24 0.68 1.9
Max 1.62 0.83 3.5
32 4
1
1 1 2 1 2 3
6
10
11 1
... 8.09 dB.
[ ] 174 10log 9 10 8.09 ( 1) 97.4
total
FF F
F F
G G G G G G
Sensitivity dBm
照理說最爛0dBm sensitivity也有-97.4以上
Gain mode G0 Min Typ Max Unit
Voltage conversion gain 49 53 57 dBV/V
PS WTR3925 LTE Gain mode 0 define by Voltage Conversion Gain need to translation to power gain
RxSAW
1.8
3.1
10
10 10
10log
10log 20log 2
IFOUT
RFIN
IFOUT IFOUT
RFIN RFIN
V
VCG
V
P V
VCG
P V
26.
Type FEL +ASM + LPF +
Dup + SP6T + Trace
eLNA Trace + RxSAW iLNA
Stage Stage1 Stage2 Stage3 Stage4
NF [dB] 4.6 1.37 2.3 2.3
Gain [dB] -4.6 11.9 -2.3 35.12
NF 2
Gain 3250.87
那我們現在來計算一下LTE B12/17的NF
And loss use max value to calculate
32 4
1
1 1 2 1 2 3
6
10
11 1
... 6.34 dB.
[ ] 174 10log 9 10 6.34 ( 1) 99.1
total
FF F
F F
G G G G G G
Sensitivity dBm
LTE B12_17 FE ASM LPF Duplexer SP6T
Typ 0.73 0.45 0.56 1.65 0.4
Max 0.98 0.55 0.56 2.35 0.5
Gain mode G0 Min Typ Max Unit
Voltage conversion gain 49 53 57 dBV/V
PS WTR3925 LTE Gain mode 0 define by Voltage conversion gain need to translation to power gain
RxSAW
1.6
2.5
w/ eLNA
27.
Type FEL +ASM + LPF + Dup + SP6T
+ Trace = loss before WTR
iLNA
Stage Stage1 Stage4
NF [dB] 5.46 2.3
Gain [dB] -5.46 35.12
NF 2
Gain 3250.87
那我們現在來計算一下LTE B12/17的NF
And loss use max value to calculate
32 4
1
1 1 2 1 2 3
6
10
11 1
... 7.76 dB.
[ ] 174 10log 9 10 7.76 ( 1) 97.7
total
FF F
F F
G G G G G G
Sensitivity dBm
LTE B12_17 FE ASM LPF Duplexer SP6T
Typ 0.73 0.45 0.56 1.65 0.4
Max 0.98 0.55 0.56 2.35 0.5
Gain mode G0 Min Typ Max Unit
Voltage conversion gain 49 53 57 dBV/V
PS WTR3925 LTE Gain mode 0 define by Voltage conversion gain need to translation to power gain
RxSAW
1.6
2.5
w/o eLNA
28.
這篇講到說升高LNA的Vcc有助於降低LNA的NF
A Single ChipSilicon Bipolar Receiver for GPS/GLONASS Applications
https://www.maximintegrated.com/en/app-notes/index.mvp/id/640
不過我們用MIPI控制的, 除非Layout, grounding沒走好造成IR drop否則應該是2.7V ?
29.
接下來討論IIP3
w/o eLNA 整體的IIP3
Type Trace ASM iLNA others
Stage Stage1 Stage2 Stage3 Stage4
IIP3 [dBm] 100 80 5 -15.5
Gain [dB] -3 -1 15 -4
IIP3 [mW] 1010 108 3.16 0.028
Gain 0.5 0.79 31.62 0.4
1 2 31 1 2
1 2 3 4
1 1
...
3 3 3 3 3
3 26.5 [dBm].
total
total
G G GG G G
IIP IIP IIP IIP IIP
IIP
w/o eLNA
Type FEL +ASM + LPF +
Dup + SP6T + Trace
eLNA Trace + RxSAW iLNA
Stage Stage1 Stage2 Stage3 Stage4
IIP3 [dBm] 80 -2 100 -10
Gain [dB] -4.6 11.9 -2.3 35.12
IIP3 [mW]
Gain
那我們現在來計算一下LTE B12/17的IIP3
And loss use max value to calculate
LTE B12_17 FE ASM LPF Duplexer SP6T
Typ 0.73 0.45 0.56 1.65 0.4
Max 0.98 0.55 0.56 2.35 0.5
Gain mode G0 Min Typ Max Unit
Voltage conversion gain 49 53 57 dBV/V
PS WTR3925 LTE Gain mode 0 define by Voltage conversion gain need to translation to power gain
RxSAW
1.6
2.5
1 2 31 1 2
1 2 3 4
1 1
...
3 3 3 3 3
3 15.1 [dBm].
total
total
G G GG G G
IIP IIP IIP IIP IIP
IIP
w/ eLNA
33.
Type FEL +ASM + LPF + Dup + SP6T
+ Trace = before WTR
iLNA
Stage Stage1 Stage4
IIP3 [dBm] 80 -10
Gain [dB] -5.46 35.12
IIP3 [mW]
Gain
那我們現在來計算一下LTE B12/17的IIP3
And loss use max value to calculate
LTE B12_17 FE ASM LPF Duplexer SP6T
Typ 0.73 0.45 0.56 1.65 0.4
Max 0.98 0.55 0.56 2.35 0.5
Gain mode G0 Min Typ Max Unit
Voltage conversion gain 49 53 57 dBV/V
PS WTR3925 LTE Gain mode 0 define by Voltage conversion gain need to translation to power gain
RxSAW
1.6
2.5
1 2 31 1 2
1 2 3 4
1 1
...
3 3 3 3 3
3 [dBm].
total
total
G G GG G G
IIP IIP IIP IIP IIP
IIP
w/o eLNA
[1] Guidelines forachieving best-in-class RX Diversity Performance in your Smartphone
Applications, Infineon
[2] Understanding and Enhancing Sensitivity in Receivers for Wireless Applications, TI
[3] Improving Receiver Sensitivity with External LNA, Maxim Integrated
[4] A Single Chip Silicon Bipolar Receiver for GPS/GLONASS Applications
[5] 80-NH379-121
[6] 80-NH379-42
[7] ATF-531P8 1900 MHz High Linearity Amplifier, AVAGO
[8] Integration of an External Low-noise Amplifier Improving the sensitivity of the Receiver, Atmel
[9] Increasing the Sensitivity of the TDA52xx Receivers, Infineon
[10] Signal Chain Noise Figure Analysis, TI
[11] Use Selectivity to Improve Receiver Intercept Point, Maxim
references