!"#$%& (")*&$+,"# -./ !"#$%& (")*&$+,"# -./ 01 2,3#4#5"6 7 8 9$ : ;$-$ <89:= 8.> 9.$#" :6?;$-$"/ <89:= Prof S. S. Jamuar Department of Electrical Engineering, Faculty of Engineering, University Malaya 50603 K l L Ml i ! 50603 Kuala Lumpur, Malaysia. [email protected]
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!"#$%&'(")*&$+,"#'-./'!"#$%&'(")*&$+,"#'-./'01'2,3#4#5"6'78 '9 $ ': ;$-$ '<89:=8.>'9.$#"':6?;$-$"/'<89:=
Prof S. S. Jamuar Department of Electrical Engineering,
Faculty of Engineering, University Malaya50603 K l L M l i
!
50603 Kuala Lumpur, [email protected]
!"#$%#$&P
I. Introduction to RF & Wireless TechnologyII Design consideration – example: LNA
Part :
II. Design consideration example: LNANoise PowerImpedance matchingImpedance matching
Resistive terminationSeries-shunt feedbackCommon gateCommon-gateInductive degeneration
III. Design procedures for Inductive Source Degeneration LNA IV D i lIV. Design examplesV. VGLNA – current modeVI. VGLNA – gain control loop
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VII. Other architectures
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Source: J. Dabrowski, Radioelectronics
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Power
Small Signal RF
PowerRF
Analog Baseband
PowerManagement
Digital Baseband
(DSP + MCU)
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Source: [2-3]
?,2#()-2>%-&(@"-(34(.!()%&2;#
• Cost• Size• Power consumption• System complexity• Time to Market
Ultimate goal: single chip CMOS RF transceiver; multi-standard.
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Ultimate goal: single chip CMOS RF transceiver; multi standard.
34(A%1$2"#(B )%&2;#(C"$$7%#%1D
Today’s mobile phones - >> 1million transistorsOnly a small fraction operate in the RF range –
l f t d (AFE)analog front-end (AFE)The rest perform low-frequency “baseband” analog and digital signal processing (DSP)analog and digital signal processing (DSP).Yet, RF section is still the design bottleneck of the entire system due to:
Multidisciplinary fieldComplex trade-offsLack of design toolsg
RFSection
BasebandSection
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Communication theoryMicrowave theory
Random signalsSignal propagation
RF DesignRF DesignTransceiversarchitectures
Multiple accessarchitectures
IC DesignWireless standards
g
CAD Toolsstandards
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34()%&2;#("1$,;"#
Noise Power
Linearity Frequencyy Frequency
RF DesignRF Design
I/O Impedance Voltage swings
Supplyvoltage
Gain
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voltage
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In power amplifier, if the supply voltage is reduced, the power dissipation increases.Gain high noise highg gNoise low nonlinearSupply voltage low non-full voltage swingSupply voltage low non full voltage swingPower dissipation low gain lowFrequency high noise highFrequency high noise high
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Computer-aided analysis and synthesis toolsComputer aided analysis and synthesis toolsNonlinearity, time variance and noiseModeling circuits in scattering (S) parametersModeling circuits in scattering (S) parameters
Tools availableAdvanced Design System (ADS) by AgilentsAdvanced Design System (ADS) by AgilentsSpectreRF by CadenceHspiceRF by SynopsysHspiceRF by Synopsys
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Wireless Local Area Network (WLAN)900 MHz, 2.4 GHz & 5.7 GHz rangeConnectivity in offices hospitals factories etcConnectivity in offices, hospitals, factories, etc
Global Positioning System (GPS)1.5 GHz rangeD t t ’ l ti di tiDetect one’s location + directions
RF Identification Systems (RF ID)900 MHz & 2.4 GHz rangeLow-cost tags attached to objects or persons to track their position.
Home satellite network10 GHz rangeSatellite television
Mobile phones
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Mobile phones
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Transmit path : signal generated by the microphone modulates a high-frequency carrier and thehigh-frequency carrier, and the result is amplified and buffered so to drive the antenna.
Receive path : signal is amplified by low-noise amplifier (LNA), the spectrum translated to lower frequency by a down-converter (mixer) for subsequent demodulation, and the demodulated output is
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amplified to drive the speaker.
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V i i l di iti d b ADCTransmit path :
Voice signal digitized by ADC.Compressed to reduce bit rate & the required bandwidth.Data undergoes “coding” & “interleaving” – format the data such that the receiver can detect & minimize errors.Data is “shaped” before it is applied to the modulator & power amplifier since rectangular pulses are not optimal for
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modulation.
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Signal is amplified, down-converted and digitized.Receive path :
Subsequently, demodulation, equalization, decoding and de-interleaving and decompression are performed.Resulting data converted to analog form by a DAC amplifiedResulting data converted to analog form by a DAC, amplified and applied to a speaker.
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Performance of these transceivers can be put in simpler form :
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Determined by power delivered to the antennasensitivity of the receiver, particularly the noise of the LNA
In analog domain, all building blocks are RF circuits except audio amplifieraudio amplifier.In digital domain, the modulator, PA, LNA and down-converter operate in the RF range.
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MNJ(2&(2FE"-$,#$O
Looking at both the transmit and receiveLooking at both the transmit and receive paths, analog signal still exists.Can’t replace the analog signal with digitalCan t replace the analog signal with digital domain.
>> Analog signal is important Th i d f LNA !!>> There is a need for LNA !!
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Built from analog
LNA
Built from analog and digital building blocks.Some sectionsSome sections pertaining RF section.
Driving force of modern RF electronics realize the whole RF section in one chipcombine this chip with a digital chip “one chip transceiver”
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combine this chip with a digital chip one chip transceiver
986(!?QA($%18#"7";6R(
Enormous support from digital market“one chip transceiver” combining the RF andone chip transceiver – combining the RF and digital/analog domain
CMOS devices achieved high cutoff frequency g q yexceeding 150 GHz for 90 nm technology [6].With multiple metal layers good capacitors and i d t (Q t 20) b i t t d hiinductors (Q up to 20) can be integrated on a chip.CMOS cheaper than other technologies (BiCMOS, GaAs )GaAs, ..).Many successful RF CMOS designs reported recently.
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Factors influencing choice of technologyFactors influencing choice of technology CMOS:
PerformancePerformanceCost time to marketLevel of integrationLevel of integrationSize / form factor
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' (
I 2 ( @( (M (N 2 (J 72@2 (
',-$(../
I%&2;#("@(,(M"=(N"2&%(JFE72@2%-(
*MNJ+
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34(&%1$2"#("@(,(-%1%2>%-
A tAntenna
Mi
LNA IF Section
BPF Mixer
RF front endLO
RF front end
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M"=HN"2&%(JFE72@2%-
Signal coming in from antenna is very small; amplification is needed gain requirement.amplification is needed gain requirement.The received signal should have certain signal-to-noise ratio to be reliably detected; noise comes from the environment and the circuit itself noise requirement.L i l bl k t th i t fLarge signal or blocker can occur at the input of LNA. Large signal performance of LNA should be good linearity requirement.good linearity requirement.Reasonable power consumption power constrain.
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Noise performanceSignificant impact domination at front endSignificant impact – domination at front end
Amplification / gainFirst stage in receiver – amplify weak signalg p y g
Impedance matchingEfficient power transferBetter noise performanceBetter noise performanceStable circuit
Power consumptionpStabilityLinearity
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; where in and vn are partially correlatedin = ic + iu ; ic = Ycvcvn = vc + vu
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N"2&%(,#,76&2&
For the MOSFET noise model, 2 sources taken into account
; = 2/3 for long channels
Correlation coefficient :
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N"2&%(,#,76&2&
Remember this!
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Alternate definition:ininin NSSNRFoutoutout NSSNR
Noise figure is the dB form of noise factor:FdBNF log10)(
As a function of device:d i NGN
source
sourcedevice
NGNGNNF
G: power gain of the device
If a system has no noise, then SNRin = SNRoutF =1 NF = 0dB.
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N4("@(1,&1,)%)(&$,;%&
Si /Ni S t/N tSin/Nin
G1, N1, Gi, Ni, GK, NK,
Sout/Nout
NF1 NFi NFK
321
1...1111 KNFNFNFNFNF
Overall NF dominated by NF1[7].
1212111 ...
...11KGGGGGG
NFNF
y 1
The noise contributed by each stage decreases as the gain preceding the stage increases.
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AF,77(&2;#,7(#"2&%(F")%7("@(,(?QA4T:
Thermal noiseRandom motion of thermally agitated charge carriers.“white” noise,
gkTfI 4)(2
: empirical constant; • 2/3 in long channel
md gkTfI 4)(
• 2-3 in short channelPMOS has less thermal noise.
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AF,77(&2;#,7(#"2&%(F")%7("@(,(?QA4T:
Flicker noise (1/f noise)Flicker noise (1/f noise)Random trapping of charge at oxide interface.“pink” noise,
K 2
K: technology –dependent parameter
fWLC
gfKfI
ox
mn 2
22 )(
K: technology –dependent parameter.At high frequency, it may be neglected; however in mixers and oscillators the 1/f-shaped spectrum can b t l t d t RFbe translated to RF range.
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Noise spectral density
1/f noise1/f noiseThermal noise
dominantThermal noise
Band of interest Frequency
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Band of interest q y
<,2#
Ratio of output signal to input signal.p g p gSmall signal amplification capability of LNA.For IC implementation
LNA input is interfaced off-chip usually matched to specific impedance (50 ohm)output is not necessary matched if it directly drive the on-output is not necessary matched if it directly drive the onchip block such as mixer.
Characterized by voltage gain or transducer power gain; power delivered to the load divided by powergain; power delivered to the load divided by power available from source.
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Relatively easy to obtain at high frequenciesMeasure voltage traveling waves with VNAMeasure voltage traveling waves with VNA
Parameters for two-port system analysisInputs and outputs expressed in terms of powersInputs and outputs expressed in terms of powers
Transmission coefficientsReflection coefficients
b1=S11a1+S12a21 11 1 12 2b2=S21a1+S22a2
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F dF d
111
bi id treflectedS 2
21
bi id t
dtransmitteS
Forward:Forward:
012a
aincident01
2aaincident
Reverse:Reverse:
222
bd
reflectedS 112
bd
dtransmitteS
Reverse:Reverse:
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0222
1aaincident
0212
1aaincident
AH',-,F%$%-&
S11 – input reflection coefficient with the output matched1
111 a
bSoutput matched
S21 – forward transmission gain or loss2bS
012a
a
S21 forward transmission gain or loss
S12 – reverse transmission or isolation
0121
2aa
S
b S12 reverse transmission or isolation
02
112
1aabS
S22 – output reflection coefficient with the input matched
02
222
1aabS
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01a
A$,C272$6(1"#)2$2"#
Necessary condition ; stability factor,
1||2
||||||1
2112
2211
222
SSSSK S
where21122211 SSSSS
Unconditionally stable if1K 1Sand
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M2#%,-2$6
Good linearity high dynamic range
Output spectrum with 2-tone input
Good linearity high dynamic rangeUsual distortion term: 2f1-f2, 2f2-f1 fall in band characterized by 3rd order non-linearity.Large in band blocker can desensitize the circuitLarge in-band blocker can desensitize the circuit.Measured by 1-dB compression point or third order input intercept point (IIP3).
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M2#%,-2$6(F%,&0-%F%#$
1dB compression pointCharacterizes circuit linearity forCharacterizes circuit linearity for large input signals.The input level that cause the small signal gain to drop by 1 dBsmall signal gain to drop by 1 dB.
IIP3Characterizes circuit linearity for C a acte es c cu t ea ty osmall input signals accompanied by strong interferers.
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Good gain (S21)L i fi (NF)Low noise figure (NF)Input matching to 50 ohm (S11)Good linearity (P1dB IIP3)Good linearity (P1dB, IIP3)Output matching to 50 ohm (S22)Good reverse isolation (S12)( )Stability (K)Low power consumptionHigh frequency operation ~ GHzMany trade-offs, very difficult to design !!
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J(&2FE7%(MNJ(%G,FE7%
AssumeNo flicker noiseio No flicker noisero= infinityCgd = 0
o
Effective transconductance :
Small signal modelinmo
meffZgiGSmall signal model :
inssmeff ZRV
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Voltage input & current output;Gain,
2
2*
*
|| inmmeff
oo
ZRZg
GVVii
G
22
*
)(1
||
mgsm
insmeff
ss
gCjg
ZRVV
2
1)(1
m
gssgss
g
CRjCjR
22 )(1 gss
m
CRg
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N4(E%-@"-F,#1%
2
2
1 ms gRgR
NF
Low frequencyR g >> ~ 1
Tms gR
Rsgm >> ~ 1gm >> 1/50 @ Rs=50 ohmPower consumingPower consuming
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No impedance matchingNo impedance matchingCapacitive input impedanceOutput not matched
Power transfer, assuming R = Rs = RL
gssRCS
111
mRgS
221
High power consumption for NF and S21
gssRCS
111gssRC121
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A Resistive terminationA. Resistive terminationB. Series-shunt feedbackC Common gate connectionC. Common-gate connectionD. Inductor degeneration
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Rs 4kT/Rsio 4kT/RI
4kT gm
Vs Is Rs Vgs gmVgsRI RI
Power gain,2
mgG
Noise figure,/1/1 gsIs CjRR
G
g
2
22111
Tsm
Ism
s
I
s RgRRg
RRRNF
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TIsmI g
!"FE,-%(=2$8(E-%>2"0&(%G,FE7%
Simple LNA NF :Simple LNA NF :
2
2
1T
msms
gRgR
NF
Resistive termination NF :Tms g
22RR
211T
smI
s
smI
s RgRR
RgRRNF
Introduced by input resistance Signal attenuated
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A0FF,-6(B -%&2&$2>%($%-F2#,$2"#
Noise performanceNoise performanceInput matched RS = RI = R and NF,
NF 42
Signal attenuatedN i i t d d th h R
RgNF
m
2
Noise introduced through RI
NF = 10 log (2) = 3 dB (best that can be done)
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PU(A%-2%&H&80#$(@%%)C,1D
Rs
RFRL RF
ioutRss
VsR
Vgs gmVgsCgs
V
RL
Broadband matching
Ra RaVs
gsaamLFi
CsRRgRRR
)1)((
Broadband matchingCould be noisy
gsLFaaLmin CRRRsRRg
R)()(1
))((1)(
))((1))(1( saFsFagssFam
out RRCRRRRRRsC
RRCRRRgR
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))((1))((1 asgsmasgsm RRsCgRRsCg
A0FF,-6(B &%-2%&(&80#$(@%%)C,1D(MNJ
For RF >> Rs, RF >> RL and gmRF >>1 the NF can be given by:
S
RRRR
NF2
111
SmSmF RgRgRBetter performance than common source amplifier.The load resistor influences the input impedanceThe load resistor influences the input impedance.Supplementary noise introduced by the RF.Need a shunt inductor to tune out C at higherNeed a shunt inductor to tune out Cgs at higher frequencies.To minimize noise, RF > RS, gmRS >> 1.
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, F S, gm S
!U(!"FF"#H<,$%(&$-01$0-%
RsRL
R 4kTR RL
4kT gms
Vs
Rs 4kTRs
VgsgmVgs
RL
outIGRs 4kTRs
RLs
outeff
gV
G
Vs Vgs gmVgs4kT gm
gm
gsssm
m
CsRRgg
1
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4kT gm
.#E0$(2FE%),#1%("@(!<(&$-01$0-%
Input impedanceInput impedance
Input impedance matchinggsmin sCgY
Input-impedance matching1/gm = Rs = 50 ohm
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222
22
)()1( gsssm
meff CRRg
gGG
2
41 mindevice gkTNGNNF
)()( gsssmg
222
2
)()1(4
1
gsssm
ms
in
CRRggkTRNG
NF
2222)1(1 gsssmms
CRRggR
2
2
41T
Si l tt t d
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Signal attenuated
A0FF,-6(B !<(A$-01$0-%
N i fNoise performanceNo extra resistive noise sourceIndependent of power consumptionIndependent of power consumption
Impedance matchingBroadband input matchingBroadband input matchingNo passive components
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IU(.#)01$"-(I%;%#%-,$2"#(A$-01$0-%
Rs Lg
V
iout
C
Rs LgZin
iVs
Ls
Vgs gmVgsCgs
Vs Ls
Vin
iin
sgsmings
inginin sLVgIsC
IsLIV )(1
sgs
inmings
ingin
gs
sLsC
IgIsC
IsLI )1(1
smsgin
gsgs
CLg
sCLLsI 1)(
Zin
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gsgs CsC
.#E0$(?,$182#;
Require for Zinto match Rsq in s
Matching criteria: )(
1gs LL
Cssm R
CLg
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criteria: )( sggs LLs
gsC
T@@%1$2>%(:-,#&1"#)01$,#1%(*<F+
)( gsmout sCgIG
m
ins
g
s
outeff
gZRV
G
= 0 @ 0
)()(1 2sggssmgss LLCsLgCRs
2222
22
)()](1[m
eff LCRLLCgGG
)()](1[ smgsssggsff LgCRLLC
mT C
gRemember:
TffG
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gsT C )( sTs
meff LRG
N"2&%(42;0-%
Calculate NF at 00
4 gkTNGN
22
2
)(4
410
ms
m
in
indevice
LgCRgkTR
gkTNG
NGNNF
22 )(1
)(
smgss
smgss
LgCRgR
LgCR
ms gR
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.#E0$(V0,72$6(4,1$"-
powerLostpowerStoredQR LI
CRRIICII
powerLost
1*
*CVCRRII
R LL 11
Cgs
Rs
Vs
LgLs
gmLs/Cgs 1
)/(11
gssmsgsin CLgRCCR
Q
Vsgm s gs
)(1
smgss LgCR
!"#$%&'(")*&$+,"#'-./'01'2,3#4#5"6'7 89:$(
N"2&%(42;0-%(=2$8(V
1Q)( smgss
in LgCRQ
0NF
22 )(1 smgssms
LgCRgR
2
11inms QgR
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A0FF,-6("@(.#)01$2>%(I%;%#%-,$2"#(
A$ $A$-01$0-%
Noise performanceNo resistive noise sourceV d i fiVery good noise figureNF decreases with the quadrature of the input quality factor
Impedance matching Matched at carrier frequency
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!,&1")%(&$-01$0-%
Reverse isolation / stabilityReverse isolation / stabilityUse cascode structure
improve SVbias
LL
M2 improve S12
reduce feedback effect of Cgd
Improve noise performanceRs Lg
2
p pDisadvantage : need a bias voltage
VsLs
M1
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Descriptions Zin Noise performance Gain
Rg4
2
StructuresZin Noise performance Gain
Resistive termination
Rs2
Lm RgRgm
2
SmSmF
S
RgRgRR
21
11
terminationSeries-shunt
feedbackLm
LF
RgRR
1
2
Lm Rg
2
2
41T
11
Common-gate connection
1/gm
Inductor Lg
Lm Rg
RQ21inms QgR
Inductor degeneration
gs
sm
CLg
Linm RQg
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oKF 1
NF equations:
T
onfKF 1
22 )14(211do Qc
gK )14(21
2 ddm
nf QcQg
K
CRQ
21
gsos CRQ
2 5d
Linearity: Voltage gain:
thgs VVIIP3S
L
o
TV R
RjAInductive degenerated CMOS LNA
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So
:,-;%$%)(AE%12@21,$2"#&
Frequency 2 4 GHz ISM BandFrequency 2.4 GHz ISM BandNoise Figure < 2 dBIIP3 8 dBIIP3 < -8 dBmVoltage gain 20 dBPower < 10mA from 1.8V
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0.18um CMOS ProcessProcess related parametersProcess related parameters
tox = 4.1e-9 m= 3.9*(8.85e-12) F/m= 3.274e-2 m2/V.s
Vth = 0.52 VNoise related parametersNoise related parameters
= gm/gdo
~ 2~ 3
c = -j0.55
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gdo increases all the way with current density IIdengm saturates when Iden larger than 120 A/ m
Velocity saturation mobility degradation shortVelocity saturation, mobility degradation ---- short channel effectsLow gm/current efficiencygm yHigh linearitydeviates from long channel value with g
large Iden
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fT increases with Vod when Vod is small and t t ft V > 0 3V h t h lsaturates after Vod > 0.3V --- short channel
effectsC /W i l l ft V 0 2VCgs/W increases slowly after Vod > 0.2VfT begins to degrade when Vod > 0.8V
gm saturatesCgs increases
Should keep Vod ~0.2 to 0.4 V
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Knf vs input Q and current density
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For fixed Id increasing Q will reduce theFor fixed Iden, increasing Q will reduce the size of transistor thus reduce total power ----noise figure will become largerg gFor fixed Q, reducing Iden will reduce power, but will increase noise figurebut will increase noise figureFor large Iden, there is an optimal Q for minimum noise figure but power may be toominimum noise figure, but power may be too high
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Linearity plots :IIP3 vs. gate overdrive and transistor size
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MOS transistor IIP3 only, when embedded intoMOS transistor IIP3 only, when embedded into actual circuit:
Input Q will degrade IIP3.Non-linear memory effect will degrade IIP3.Output non-linearity will degrade IIP3.
IIP3 is a very weak function of device sizeIIP3 is a very weak function of device size.Generally, large overdrive means large IIP3
But the relationship between IIP3 and gate overdrive is notBut the relationship between IIP3 and gate overdrive is not monotonic.There is a local maxima around 0.1V overdrive.
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Small current budget ( < 10mA ) does not allow largeSmall current budget ( < 10mA ) does not allow large gate overdrive :
Vod ~ 0.2 V ~ 0.4 Vf 40 45 GH
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fT ~ 40 ~ 45 GHz
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Gm/W~0.4
S l t I 70 A/ >V 0 23V
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Select Iden = 70 A/ m, =>Vod~0.23V
If Q = 4, IIP3 will have enough margin:Q , g gEstimated IIP3:IIP3(from curve) – 20log(Q) = 8-12 = -4dBmSpecs require: > 8 dBm
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Specs require: >-8 dBm
Q=4 and Iden = 70 A/ m meet thenoise figure requirement
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Some calculations:C 1mfFWCgs /3.1 fF
QRC
oSgs 166
21
fF166 mmfF
fFW 128/3.1
166
AAI 98/70128
Verifying cutoff frequency;
mAmAmIDS 9.8/70128
GHzCgf
gs
mT 482mSgm 501284.0
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nHR
L Ss 2.0
T
nHLL S 261 nHLC
L Sgso
g 262
LTV R
RjA 30SVo
L RARSo R
T
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SParameter Target SimulatedNoise Figure 1.6 dB 0.8 dBDrain Current < 10mA 8 mAVoltage gain 20 dB 21 dBIIP3 -8 dBm -6.4 dBmP1dB -20dbmS11 -17 dBPower supply 1.8 V 1.8 V
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Step-by-step:1 Process parameters1. Process parameters2. Design guide plots3. Cutoff frequency, fT4. Current density Iden, Q and device sizes5. Inductors values – Lg, Ls and RL
6 Simulation verification6. Simulation verificationEquations and simulation plots needed in order to meet design specifications.g pSeveral iterations between calculations and simulations required to achieve satisfactory result.
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Objective is to design Variable Gain LNA (VGLNA) that would:that would:
Provide sufficient gain Typically 10 dB < gain < 20 dB
Minimize noise contributionNF ~ 2 dB
Good linearity performanceGood linearity performanceConsume minimum powerDesire to have variable gain amplificationg p
High dynamic range of the input signals
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Vbias
Vdd
Ld
Rbias Cu Lu
RFoutI3 I4Vb
M2M3 M4
Rb
ClRFoutVb
LgCi
M1
RFin
1st stage 2nd stage
Ls
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1st stage 2nd stage
X&$ &$,;%(H MNJ
The cascode architecture Vdd
provides a good input –output isolation.T i t M i l t thM2
Ld
ClRFout
Transistor M2 isolates the Miller capacitance.Input Impedance isM1
M2
Rb
Vb
Input Impedance is obtained using the source degeneration inductor Ls. G t i d t L t th
Ls
LgCiRFin
Gate inductor Lg sets the resonant frequency.
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$ 8 2 (.$%18#250%^(.\Consisted of M3, M4 and LC load.M3 t bi ltM3 converts bias voltage, Vbias to the drain current signal, I3.Gain amplified and controlledRbias Cu Lu
Vbias
Vdd
Gain amplified and controlled through geometry ratio of M4/M3 which influences current, I4,3.M3 M4 Cl
RFoutI3 I4
,
From_LNA_stage'3
'4
3
4
2
3
4
43
43
3
4
11
KK
vv
VVVV
LWWL
II
ADS
DS
TGS
TGSi
WLI
Lu & Cu used for output 43
43
3
4
LWWL
II
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The gain S21 changes with changes with Vbias changes from 1.0 to 1.8 V, reporting tuning range of 27.98 dB; from g g g-7.7 20.08 dB.
When Vbias = 1.8 V: SImulated
When Vbias = 1.0 V: Simulated
Measured
M dMeasured
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Description Units Measured data ( )
Simulated data( )( ) ( )
Vbias V 1.0 1.8 1.0 1.8
Gain, S21 dB -7.699 20.082 20.226 25.576
S11 dB -7.902 -10.045 -11.348 -11.348
S12 dB -11.591 -7.046 -72.913 -68.831
S22 dB 2.409 11.093 -2.67 -4.88
Gain variation dB 27.981 5.35
Power dissipation mW 60.0 48.1
NF dB 4.417 1.560
IIP3 dBm 16.451 16.080
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<,2#(1"#$-"7(7""EC i t d f t i t M d
Vdd
Consisted of a transistor Mgcand a capacitor Cf.If Mgc is turned off, the gain control loop acts like an open
Lo
Vdd
Vc
control loop acts like an open circuit minimum gainIf Mgc is turned on with sufficiently high voltage (like
CLCf
Mgc
OutIn
y g g (VDD), the Mgc operates as a bypass switch maximum gainControl voltage of Mgc is between V and V acts like a variable
M4
VT and VDD acts like a variable resistor.Resistance equal to channel R;
gcthgscoxn
gc
VVVL
WCR
4
1
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Vdd
c
Ld
c
Lo
RFout
Vc
M2CLCf
M4
Mgc
Vb
Lg
M1Rb
CRFin
Ls
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Description Unit Measured data ( )
Simulated data( )( ) ( )
Controlled voltage, Vc
V 0.5 1.0 0.5 1.0
Gain S dB 17 828 13 161 8 631 22 185Gain, S21 dB 17.828 13.161 8.631 22.185
S11 dB -1.303 -1.197 -19.361 -18.503
S12 dB -50.828 -54.638 -60.221 -60.08
S22 dB -2.396 -3.703 -0.091 -0.444
Gain variation dB 4.667 13.554
NF dB 0.812 1.916 1.125 1.116NF dB 0.812 1.916 1.125 1.116
IIP3 dBm 3.61 4.636 -2.178 -2.609
Power dissipation mW 5.55 15.3 4.28 12.4
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By adding a simple gain control loop composed of Mgc and Cf, a 2.4 GHz VGLNA achieves gain tuning range of 4.67 dB.
!"#170&2"#
Overviews of RF subsystemBuilding blocks of wireless transceiverAnalog digital & RF fieldsAnalog, digital & RF fieldsWireless applications
RF front-end circuits, typically LNAParameters for noise power impedance matchingParameters for noise, power, impedance matching
Procedures on designing an inductive source degeneration LNAStep-by-step
Design examplesDesign examplesDesign methods and techniques
current mode for VGLNAproposed gain control loop for VGLNAp p g p
Other architecturesDifferential, combined current reuse, inter-stage inductor and folded cascode
!"#$%&'(")*&$+,"#'-./'01'2,3#4#5"6'7 89:((
3%@%-%#1%&/1. http://www.ek.isy.liu.se/~jdab2. T. Manku, G. Beck and E. J. Shin, “A Low-Voltage Design Technique for RF Integrated
Circuits,” IEEE Trans. On Circuits and System, vol. 45, Oct. 1998, pp. 1408-1413.3. http://bwrc.eecs.berkeley.edu/
B R i “Ch ll i P t bl RF T i D i ” IEEE Ci it d D i4. B. Razavi, “Challenges in Portable RF Transceiver Design,” IEEE Circuits and Devices Magazine, vol. 12, Sept. 1996, pp. 12-25.
5. http://www.ee.ualberta.ca/~igor/6. C.-S. Chang, C.-P. Chao, J. G. J. CHern and J. Y-C. Sun, “Advanced CMOS Technology
Portfolio for RF IC Applications,” IEEE Trans. Electron Devices, vol. 52, no. 7, July 2005, pp. 1324 13341324-1334.
7. F. Friis, “Noise Figure of Radio Receivers,” Proc. IRE, vol. 32, July 1944, pp. 419-422.8. D. Shaeffer and T. Lee, “A 1.5-V, 1.5 GHz CMOS Low Noise Amplifier,” IEEE J. Solid-State
Circuits, vol. 32, May 1997, pp. 745-759.9. A. Karanicolas, “A 2.7 V 900-MHz CMOS LNA and Mixer,” IEEE J. Solid-State Circuits, vol. 31,
Dec 1996 pp 1939 1944Dec. 1996, pp. 1939-1944.10. http://amesp02.tamu.edu/~sanchez/11. F. Gatta, E. Sacchi, F. Svelto, O. Vilmercati and R. Castello, “A 2-dB Noise Figure 900-MHz
Differential CMOS LNA,” IEEE J. Solid-State Circuits, vol. 36, Oct. 2001, pp. 1444-1452.12. Y.S. Wang and L.-H. Lu, “5.7 GHz low-power variable-gain LNA in 0.18 µm CMOS,”
Electronics Letters vol 41 Jan 2005 pp 66 68Electronics Letters, vol. 41, Jan. 2005, pp. 66-68.13. M.-D. Tsai, R.-C. Liu, C.-S Lin and H. Wang, “A Low-Voltage Fully-Integrated 4.5-6 GHz CMOS
Variable Gain LNA,” 33rd European Microwave Conference, Munich, vol. 1, pp. 13-14, Oct. 2003.
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