rf front end radio design- simulations and specifications
DESCRIPTION
RF Front End Radio Design- Simulations and Specifications. Hemish Parikh Advisor: Prof. William R. Michalson. RF Front End Receiver Design - Outline. Outline. Overview System parameters Specifications System Analysis System Parameter relations System Simulations in ADS Roadmap - PowerPoint PPT PresentationTRANSCRIPT
RF Front End Radio Design-Simulations and Specifications
Hemish ParikhAdvisor: Prof. William R. Michalson
04/22/23 2
Outline• Overview• System parameters• Specifications• System Analysis• System Parameter relations• System Simulations in ADS• Roadmap• Questions
RF Front End Receiver Design - Outline
04/22/23 3
Filters, Amps
Mixers, Osc
Analog Front End Location Estimate
A/D, Latches,
SDRAM
Digital Back End
Vin
GND
Vref
D1
D4
Sign
ENB
Vref
FB
Comp
Reset
I-sense
Drain
Source
Shtdwn
Interface
Overview
RF Front End Receiver Design - Overview
You are Here
04/22/23 4
Today’s Focus
A/DAMP
LO
BPF MIXER DSPLPF
Possible Front End ModelsPossible Front End Models• Model 1: Direct RF Sampling
• Model 2: Direct Down Conversion
A/DAMPBPF DSP
880 MHz
RF Front End Receiver Design - Overview
04/22/23 5
System Parameters
• System Gain (G)• System Noise Figure (NF)• Input 3rd Order Intercept Point (IIP3)• Receiver Sensitivity (Rx-Sens)• Receiver Spurious Free Dynamic Range
(SFDR)• Inter Modulation Distortion (IMD)
RF Front End Receiver Design – System Parameters
04/22/23 6
Component Identification
AGC
VCO
BPF MIXER LPF
PLL
TCXO
LNA
0-50 MHz
COMTELCO
PEXW-400
MURATA
415-465 MHz
ANALOG DEVICES
AD-8343
MURATA
0-50 MHzVARI-L
VCO190-445T
VECTRON
OSC-1B0-10MHzANALOG DEVICES
ADF-4112
ANALOG DEVICES
AD-8367
RF MICRO DEVICES
RF-2361
RF Front End Receiver Design - Specifications
04/22/23 7
Specifications - LNA
• RFMD – 2361– Low Noise Figure (NF): 1.9 dB– Gain (G): 20 dB– Input 3rd order intercept point (IIP3): 6 dBm– Max input RF level: +10 dBm
AGCBPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design - Specifications
04/22/23 8
Specifications - AGC
• AD 8367:– Variable Gain:
-2.5 dB to 42.5 dB– NF ???– IIP3 ???
AGCBPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design - Specifications
mVmVVVdBGain
Gain
Gain
95050550)(
04/22/23 9
Specifications – Mixer (1)
• Big role in overall system performance• Mixing is just frequency shifting• Produces LO+RF and LO-RF• Produces Unwanted Inter Modulation Distortion (IMD)• IM products: (M*LO + N*RF) and (M*LO - N*RF)• Good Mixer or a Bad Mixer !!!!!????
RFLO
LO-RF LO+RF
IM Products
RF Front End Receiver Design - Specifications
04/22/23 10
Good Mixer
Low Noise Figure (< 15dB)
Good Port Isolation (~ 50dBm)
High IP3 ( > 15dB)
High Conversion Gain
LO drive level (application dependent)
RF Front End Receiver Design - Specifications
Specifications – Mixer (2)
04/22/23 11
• AD 8343:– NF: 11 dB– Gain: 7.1 dB– IIP3: 20 dBm– LO drive level: -10 dBm
AGCBPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design - Specifications
Specifications – Mixer (3)
04/22/23 12
MIXER
m14freq=dBm(V_input)=-9.172
40.00MHz
0.5 1.0 1.5 2.0 2.5 3.00.0 3.5
-200
-100
-300
0
freq, GHz
dBm
(V_i
nput
)
Readout
m14 Mixer Input
m1freq=dBm(Vmix)=-15.926
440.0MHzm7freq=dBm(Vmix)=-12.433
360.0MHz
0.6 1.1 1.6 2.1 2.6 3.10.1 3.5
-100
-50
-150
0
freq, GHz
dBm
(Vm
ix)
Readout
m1
Readout
m7Mixer Output
RF Front End Receiver Design - Specifications
Specifications – Mixer (4)
LO = 400 MHz
04/22/23 13
Specifications - TCXO / VCO
• Vectron TCXO:
– Frequency: 10 MHz– Stability: 2.5 ppm– Mechanical Trip:
+/- 3 ppm
• Vari-L VCO:
– Tuning Range: 400 to 500 MHz
– Tuning Sensitivity: 15MHz/V
AGC
VCO
MIXER
PLL
TCXO
LNA
RF Front End Receiver Design - Specifications
04/22/23 14
Specifications – PLL (1)
• ADF 4113:– Programmable
counters: P, B, A, R
AGC
VCO
MIXER
PLL
TCXO
LNA
RfABPf TCXOvco /
RF Front End Receiver Design - Specifications
04/22/23 15
System Gain
G1= -2dB G2= 20dB G3= 7.1dB G4= -2dB
BPF LNA MIXER LPF
P_in (dBm) -40 -42 -22 -14.9
Gain (dB) -2 20 7.1 -2
Cumulative Gain -2 18 25.1 23.1
P_out (dBm) -42 -22 -14.9 -12.9
G(dB) = G1+G2+G3+G4
P_in = G + P_out
BPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design – Analysis
04/22/23 16
System Noise Figure (1)Noise Sources
System Noise Thermal Noise
System noisy due to losses in circuit, solid state devices.
Noise Figure quantifies
how noisy the system is
Noise Figure is Noise Factor in dB
GOAL: Design receiver with lowest NF !!!!!!
Reference Max allowed NF: WCDMA: 9 dB
Cellular: 10 dB PCS: 6.8 dB
RF Front End Receiver Design – Analysis
04/22/23 17
System Noise Figure (2)
BPF LNA MIXER LPF
NF (dB) 2 1.9 11 2
Cumulative NF (dB)
2 3.9 4.21 4.22
.....1
1
21
GNFNFNFNoise Figure of Cascaded System
NF1=2dB NF2=1.9dB NF4=11dB NF5= 2dB
G1= -2dB G2= 20dB G3= 7.1dB G4= -2dB
BPF MIXER LPFLNAP_in P_out
Critical
RF Front End Receiver Design – Analysis
04/22/23 18
System Input IP3 (1)
IP3 is a measure of system linearity. Point where the desired signal and the 3rd order
distortion have equal magnitudes.
Third Order products: 2f1+f2, 2f1-f2, 2f2+f1, 2f2-f1, where f1 and f2 are two
inputs.
Problem: Relatively large magnitude and difficult to filter
Reference Min allowed IIP3:Cellular: -13 dBmPCS: -11.425 dBm
RF Front End Receiver Design – Analysis
04/22/23 19
System Input IP3 (2)
G1= -2dB G2=20dB G3=7.1dB G4= -2dB
IIP1= dBm IIP2= 6dBm IIP3=20dBm IIP4= dBm
1
43213
1111log10
IPIPIPIPIIP
dBm1.1)28.1log(10
16.1
131.611log10
1
BPF MIXER LPFLNAP_in P_out
Critical
RF Front End Receiver Design – Analysis
04/22/23 20
Rx. Sens = Noise Floor + 10log(BW) + SNR_min + Noise Figure
Significantly reducesThe Rx. Sens
Receiver Sensitivity (1)• Rx. Sens quantifies the receivers ability to respond
to weak signal.
Rx. Sens = -174 + 77 + 12 + 4.22 = -80.78 dBm
SNR_min = 12dB (Assume)BW = 50MHz
RF Front End Receiver Design – Analysis
BPF MIXER LPFLNAP_in P_out
A/DInput
04/22/23 21
Receiver Sensitivity (2)
RF Front End Receiver Design – Analysis
As BW increases, sensitivity becomes poor
04/22/23 22
Receiver Sensitivity (3)
RF Front End Receiver Design – Analysis
04/22/23 23
Receiver Spurious FreeDynamic Range
• High DR means Receiver can operate over wide range of input power levels.– Receiver’s Output starts to saturate if the Input is above
the range– Below DR, the noise dominates.
SFDR = 0.66 (IIP3 – Rx. Sens)
= 0.66 (1.1 + 80.78)
= 54.6 dB
RF Front End Receiver Design – Analysis
04/22/23 24
AGC Issues
• Max AGC Gain: – Lowest NF– Lowest IIP3
RF Front End Receiver Design – Analysis
• Min AGC Gain: – High IIP3– High NF
• Poor Dynamic Range: 25dB
04/22/23 25
DynamicRange
dBm
NoiseFigure
Min SNRReqd
Approx:IP3-15
Min Reqd Rx.Signal Level
Effective Rx. Noise= -90dBm
Thermal NoiseFloor
System Parameters Relations
Application Dependent
Maximize Rx. Sens
Maximize DR
Higher IP3
Bandwidth Dependent
Minimize NF
RF Front End Receiver Design – Parameters Relations
04/22/23 26
ADS simulations for Gain (1)
m2Component=our_bgain[0::x,0]=22.375
b6
b2_AMP1 b3_MIX1 b5_BPF2b1_BPF1 b6
0
10
20
-10
30
Component
our_
bgai
n[0:
:x,0
]
Readout
m2Gain in the Receive RF chain
BPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design - Simulations
04/22/23 27
ADS simulations for Gain (2)
m1Component=our_bgain[0::x,0]=22.018
b6
b2_BPF1 b3_MIX1 b5_BPF2b1_AMP1 b6
0
10
20
-10
30
Component
our_
bgai
n[0:
:x,0
]
Readout
m1Gain in the Receive RF chain
MIXERBPF LPFLNAP_in P_out
Swapped
RF Front End Receiver Design - Simulations
04/22/23 28
ADS simulations for NF(1)
m1Component=our_bnf[0::x,0]=4.259
b6
b2_AMP1 b3_MIX1 b5_BPF2b1_BPF1 b6
1
234
0
5
Component
our_
bnf[0
::x,0
]
b64.259
m1NF in the Receive RF chain
BPF MIXER LPFLNAP_in P_out
RF Front End Receiver Design - Simulations
04/22/23 29
ADS simulations for NF(2)MIXERBPF LPFLNA
P_in P_out
Swapped m5Component=our_bnf[0::x,0]=2.468
b6
b2_BPF1 b3_MIX1 b5_BPF2b1_AMP1 b6
0.5
1.0
1.5
2.0
0.0
2.5
Component
our_
bnf[0
::x,0
]
Readout
m5NF in the Receive RF chain
RF Front End Receiver Design - Simulations
04/22/23 30
BPF2_in
Mix2_in LPF1_in
Mix1_in BPF1_in
LPF1_out
Amp1_in
Amp2_in
Link1_in
MixerIMTMIX2
IMT_File="dbl1.imt"LoThresh=NF=11 dBS33=0.S22=0.3S11=0.3ConvGain=dbpolar(7.1,0)
MixerIMTMIX1
IMT_File="dbl1.imt"LoThresh=NF=17 dBS33=0.S22=0.3S11=0.3ConvGain=dbpolar(7.1,0)
BPF_ChebyshevBPF1
IL=2 dBBWstop=100 MHzBWpass=80 MHzFcenter=440 MHz
LPF_ButterworthLPF1
IL=2 dBAstop=20 dBFstop=75 MHzApass=3 dBFpass=50 MHz
AmplifierAMP1
S12=0.S22=0.3S11=0.3S21=dbpolar(33,0)
LOS_LinkLINK1
PathLength=10 meterRxVSWR=1.5RxGain=1 dBTxVSWR=1.5TxGain=1 dBBW=112 MHzCenterFreq=440 MHzP_1Tone
SRC2
Freq=465 MHzP=dbmtow(0)Z=50 OhmNum=3
TermTerm1
Z=50 OhmNum=2
BPF_ChebyshevBPF2
IL=2 dBBWstop=75 MHzBWpass=50 MHzFcenter=440 MHz
P_nTonePORT5
P[5]=dbmtow(-10)P[4]=dbmtow(-10)P[3]=dbmtow(-10)P[2]=dbmtow(-10)P[1]=dbmtow(-10)Freq[5]=45 MHzFreq[4]=35 MHzFreq[3]=25 MHzFreq[2]=15 MHzFreq[1]=5 MHzZ=50 OhmNum=5
AmplifierAMP2
S12=0.S22=0.3S11=0.3S21=dbpolar(20,0)
P_1ToneSRC3
Freq=465 MHzP=dbmtow(7)Z=50 OhmNum=4
ADS simulations for IMD (1)
RF Front End Receiver Design - Simulations
04/22/23 31
ADS simulations for IMD (2)
0.2 0.4 0.6 0.8 1.0 1.20.0 1.4
-100-80-60-40-20
-120
0
freq, GHz
dBm
(Mix
1_in
)
Original Signal
0.2 0.4 0.6 0.8 1.0 1.20.0 1.4
-100-80-60-40-20
-120
0
freq, GHz
dB(B
PF1_
in)
UpConvertion Mixer Output
300 500 700100 900
-300
-200
-100
0
-400
50
freq, MHz
dBm
(Lin
k1_i
n)
Transmitted Signal
RF Front End Receiver Design - Simulations
300 500 700100 900
-400
-300
-200
-100
-500
0
freq, MHz
dBm
(Am
p2_i
n)
Receiver LNA input
04/22/23 32
ADS simulations for IMD (3)
200 400 6000 800
-100-80-60-40-20
0
-120
20
freq, MHz
dBm
(Mix
2_in
)
Downconverter Mixer Input
200 400 6000 800
-100-80-60-40-20
0
-120
20
freq, MHz
dBm
(LPF
1_in
)
Downconverter Mixer Output
0.2 0.4 0.6 0.8 1.0 1.20.0 1.4
-250-200-150-100-50
-300
0
freq, GHz
dBm
(LPF
1_ou
t)
LPF output
0.2 0.4 0.6 0.8 1.0 1.20.0 1.4
-250-200-150-100-50
-300
0
freq, GHz
dBm
(Mix
1_in
)
Original Signal
RF Front End Receiver Design - Simulations
04/22/23 33
ADS simulations for SFDR
0.2 0.4 0.6 0.8 1.0 1.20.0 1.4
-100-80-60-40-20
-120
0
freq, GHz
dBm
(LPF
1_ou
t)
LPF output
RF Front End Receiver Design - Simulations
Rx Signal Level = -25dBm
SFDR ~= 50 dB
SFDR
04/22/23 34
RF Front End Receiver Design - Simulations
04/22/23 35
Roadmap
• ADS with Matlab• ADS with Instruments• Set-up Evaluation board• Migrate to 2.4 GHz
RF Front End Receiver Design
04/22/23 36
RF Front End Receiver Design
?