designing stability into 1296 mhz and 2304 mhz low noise ... · using an atf-36077 followed by an...

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Designing Stability into 1296 MHz and2304 MHz Low Noise Amplifiers

By Al Ward W5LUA & Tommy Henderson WD5AGO

July 28, 2007

Central States VHF Society

San Antonio, Texas

Wireless Semiconductor Division

What do we want from an LNA?

Low noise figure < 0.4 dB

High gain > 35 dB

Good input and output match – minimizes interactions withother stages

Stable – must not oscillate when connected to antenna

Cascadable


What makes a good second stage?

Low noise figure < 0.8 dB NF

Enough gain to make cascade about 30 to 35 dB

Good broadband match for first stage

Stable


Today’s Transistors

Today’s transistors have very low noise figures andvery high gain

High gain contributes to stability problems anddecreased input intercept point

Minimum input VSWR and minimum noise figure willgenerally not occur simultaneously with samematching network. Use of source inductance may helpbut too much may cause instability


ATF-3XXXX Series of PHEMTsDepletion mode PHEMT technology – requires negativevoltage on gate wrt source

Ceramic and plastic surface mount packaging

Various gate widths 200u / 400u / 800u / 1600 u

At lower frequencies, I.e. 2 GHz or less, larger gate widthsoffer lower gain and lower impedances which cancontribute to improved stability and lower matching circuitlosses

360

G

D

SSATF-36077 – 200 u

ATF-35143 – 400 uATF-34143 – 800 uATF-33143 – 1600 u


ATF-5XXXX Series of PHEMTs

Enhancement mode PHEMT technology – requires positivevoltage on gate wrt source

Plastic surface mount packaging

Various gate widths 400u / 800u and larger

Noise figure of enhancement mode devices 0.1 to 0.2 dBhigher than depletion mode devices

ATF-55143 – 400 uATF-54143 – 800 u


What about S-parameters?!??!

A three-terminal two-port, such as theFET shown, has four S-parameters.

Snn = voltage reflection coefficient,both amplitude and phase relative to50source impedance

S21 and S12 are commonly displayed ona polar chart.

S11 = input displayed on Smith chart

S22 = output displayed on Smith chart

S21

S12

S11S22

Polar chart Smith chart


What about Noise Parameters?!??!

o (Gamma Opt) is the reflectioncoefficient of the source impedancepresented to the device that allowsthe device to produce its’ fmin

Matching circuit losses often limit theability of the amplifier to achieve anoise figure equivalent to device fmin

o not necessarily equal to S11* whichmeans noise match is not equivalentto a gain match

Rn (Noise Resistance) is used tocalculate the device’s sensitivity innoise figure to changes in sourceimpedance, rn is normalized to 50 .

For minimum NF, in = oFor maximum gain, in = S11*

in

Q1

Impedance MatchingNetwork


Other measures of input characteristicsVSWR = Voltage Standing Wave Ratio

Return Loss

Mismatch Loss

1

1VSWR

2log10RL

ML = 10 LOG (1 - 2)


Input Impedance Match

Match to opt for minimumnoise figure

Noise degrades in circularcontours as match moves awayfrom opt

Degree of noise degradation isdependent on Rn, the noiseresistance

Most amateur applications aimfor minimum noise figure andaccept input VSWR

S11*

opt

in

Q1

Impedance MatchingNetwork


Simultaneous Input VSWR and Noise Match

new S11*

newopt

Adding source inductancerotates opt towards S11*

Source inductance is seriesfeedback which effects gain andstability

Its’ effect must be analyzed overas a wide a bandwidth as thedevice has gain


Output Impedance Match

S22’* = L is the reflection coefficient of

the output matching network withinput terminated in opt, not 50

Match to S22’* = L for best gain/output

VSWR

LNA may not be unconditionallystable when matched for best outputVSWR - Some resistive loading maybe required to reduce gain to improvestability

Best output VSWR does notnecessarily guarantee best P1dB andIP3.

S22*

S22'*

L = S22 + S12 S21 o1 - S11 o

*


Using AppCAD for Circuit Analysis

http://www.avagotech.comAvailable for freedownload at


ATF-36077 vs ATF-33143 Stability Factors vs Freq.Stability Factor Kcalculated from S

parameters at eachfrequency, K>1 for

unconditional stability

ATF-36077 – K < 1 atall frequencies below

10 GHz

ATF-33143 – K < 1only below 4.2 GHz,making the deviceless sensitive to

source grounding –better for VHF LNAs

2112

2222

211

21

SSDSS

K

21122211 SSSSD


ATF-36077 vs ATF-33143S21 vs MAG vs MSG

S21 = 50 Gain

MAG = MaximumAvailable Gainapplies when K>1

MSG = MaximumStable Gain


Contributions to Source Inductance

1. Lead length from edgeof transistor package tobypass cap or platedthrough hole addsinductance2. Use of a source resistorbypass capacitor can altercircuit stability3. The inductanceassociated with the bypasscapacitor and theequivalent inductance dueto the thickness of printedcircuit board

LL LL

PCB


AN 1128 ATF-36077 L Band LNA

December 1996


Single stage ATF-36077

2 4 6 8 10 12 14 16 180 20

-30

-20

-10

0

10

20

-40

30

freq, GHz

dB(S

(2,1

))

m1

m1freq=dB(S(2,1))=18.432

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHzS

tabF

act

1

2 4 6 8 10 12 14 16 180 20

-2.5

-2.0

-1.5

-1.0

-0.5

-3.0

0.0

freq, GHz

dB(S

(1,1

))

2 4 6 8 10 12 14 16 180 20

-25

-20

-15

-10

-30

-5

freq, GHz

dB(S

(2,2

))

m2freq=nf(2)=0.349

1.300GHz

0.10.20.30.40.50.60.70.80.91.01.11.21.31.41.51.61.71.81.9

-0.0

2.0

0.5

0.0

1.0

freq, GHz

nf(2

)

m2

m2freq=nf(2)=0.349

1.300GHz

m1freq=dB(S(2,1))=18.432

1.300GHz


2 Stages ATF-36077 Connected with 4.5 inches of 50ΩCoax

m1freq=dB(S(2,1))=34.703

1.300GHz

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

40

-80

60

freq, GHz

dB

(S(2

,1))

m1

m1freq=dB(S(2,1))=34.703

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Sta

bFa

ct1

2 4 6 8 10 12 14 16 180 20

-6

-4

-2

0

-8

2

freq, GHz

dB

(S(1

,1))

2 4 6 8 10 12 14 16 180 20

-25

-20

-15

-10

-5

-30

0

freq, GHz

dB

(S(2

,2))

m2freq=nf(2)=0.354

1.300GHz

0.10.20.30.40.50.60.70.80.91.01.11.21.31.41.51.61.71.81.9

-0.0

2.0

0.5

0.0

1.0

freq, GHz

nf(

2)

m2

m2freq=nf(2)=0.354

1.300GHz

Simulation suggests potential stability concerns


Better approach is a WD5AGO integrated 2 stage amplifierusing an ATF-36077 followed by an ATF-34143 or ATF-54143

MSTEPStep2

W2=10.0milW1=100.0milSubst="MSub1"

MLINTL13

L=80.0milW=100.0mil

Subst="MSub1"

SRLCSRLC4

C=470.0pFL=.5nHR=.3Ohm

MLIN

TL3

L=700.0milW=10.0milSubst="MSub1"

RR3R=50Ohm

LL1

R=

L=40nH

VIA2

V5

W=25.0milRho=1.0T=0.7mil

H=62.0milD=15.0mil

VIA2

V6


H=62.0milD=15.0mil

VIA2

V7


H=62.0milD=15.0mil

VIA2

V8


H=62.0milD=15.0mil

VIA2V4

W=25.0mil

Rho=1.0T=0.7milH=62.0mil

D=15.0mil

VIA2V3

W=25.0mil


D=15.0mil

VIA2V2

W=25.0mil


D=15.0mil

VIA2V1

W=25.0mil


D=15.0mil

MSUBMSub1

Rough=0mil

TanD=.02T=.7milHu=3.9e+034mil

Cond=1.0E+50Mur=1Er=4.5H=62.0mil

MSub

MLINTL12


MSTEPStep1

W2=100.0milW1=10.0mil

Subst="MSub1"INDQL3

Rdc=0.0Ohm

Mode=proportional to freqF=100.0MHzQ=50.0

L=220nH

MLINTL4

L=500.0milW=10.0mil

Subst="MSub1"

MLIN

TL5

L=25.0mil

W=20.0milSubst="MSub1"

MLIN

TL6

L=25.0mil


SRLCSRLC10

C=1000pFL=.5nHR=.3Ohm

RR7

R=75Ohm

RR6R=50Ohm

MLINTL7

L=700.0milW=10.0mil

Subst="MSub1"

SRLCSRLC9


SRLCSRLC8


TermTerm2

Noise=yesZ=50OhmNum=2

RR5

R=10Ohm

SRLCSRLC7


SRLCSRLC6


S2PSNP2

File="C:\S_DATA\FET\f331434e.s2p"

21

Ref

RR4R=50Ohm

MLINTL11


SRLCSRLC5


MLINTL10


MLINTL9


RR2

R=20Ohm

MLINTL8


MLIN

TL2

L=15.0mil


MLIN

TL1

L=15.0mil


StabFactStabFact1StabFact1=stab_fact(S)

StabFact

RR1R=470Ohm

SRLCSRLC3

C=470.0pF

L=.5nHR=.3Ohm

SRLC

SRLC2

C=7.0pF

L=.25nHR=.2Ohm

S2PSNP1

File="C:\S_DATA\FET\F360772A.S2P"

21

Ref

L

L2

R=L=47nH

SRLCSRLC1


TermTerm1


Resistive LoadingSource Inductance


ADS Optimized ATF-36077 First Stage

MSUBMSub1

Rough=0 milTanD=.02T=.7 milHu=3.9e+034 milCond=1.0E+50Mur=1Er=4.5H=31mil

MSub

SRLCSRLC4

C=1000pFL=1.4 nHR=.3 Ohm

MLINTL3

L=250 milW=10.0 milSubst="MSub1"

MSTEPStep2

W2=10.0 milW1=150.0 milSubst="MSub1"

MLINTL13

L=150.0 milW=150.0 milSubst="MSub1"

RR3R=50Ohm

SRLCSRLC5

C=10 pFL=.25 nHR=.2 Ohm

SRLCSRLC3

C=1000 pFL=1.4 nHR=.3 Ohm

RR1R=50 Ohm

SRLCSRLC2

C=10.0pFL=.25 nHR=.2 Ohm

MLINTL2


MLINTL1


RR2R=10 Ohm

MLINTL8


MLINTL9


VIA2V4

W=25.0 milRho=1.0T=0.7 milH=31.0 milD=15.0 mil

VIA2V3

W=25.0milRho=1.0T=0.7 milH=31.0milD=15.0mil

VIA2V2


VIA2V1


LL1

R=L=40 nH

MLINTL10


S2PSNP1File="C:\S_DATA\FET\F360772A.S2P"

21

Ref

LL2

R=L=47 nH

SRLCSRLC1

C=3.3 pFL=.25 nHR=.2 Ohm

TermTerm1

Noise=yesZ=50 OhmNum=1


ADS Optimized ATF-36077 First Stage

1 20 3

0.5

1.01.52.02.5

3.03.54.04.5

0.0

5.0

freq, GHz

nf(2

)

m1

m1freq=nf(2)=0.354

1.300GHz

2 4 6 8 10 12 14 160 18

-20

-15

-10

-5

-25

0

freq, GHz

dB(S

(1,1

))

m3

dB(S

(2,2

))

m4

m3freq=dB(S(1,1))=-2.824

1.300GHzm4freq=dB(S(2,2))=-6.779

1.300GHz

2 4 6 8 10 12 14 160 18

-20

-10

0

10

20

-30

30

freq, GHz

dB(S

(2,1

))

m2m2freq=dB(S(2,1))=22.880

1.300GHz

2 4 6 8 10 12 14 160 18

0123456789

-1

10

freq, GHz

Sta

bFac

t1

m5

m5freq=StabFact1=0.318

910.0MHz

This is about the best that can be had in stability if NF is not to be compromised


Let’s take a look at second stage candidates

ATF-36077 200 u gate width depletion mode device



ATF-54143 400 u gate width enhancement mode device

Other candidates


Optimized ATF-54143 Second Stage

1 20 3

0.51.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.0

5.0

freq, GHz

nf(2

)

m1

m1freq=nf(2)=0.492

1.300GHz

2 4 6 8 10 12 14 160 18

-30

-20

-10

-40

0

freq, GHz

dB(S

(1,1

))

m3

dB(S

(2,2

))

m4

m3freq=dB(S(1,1))=-7.908

1.300GHzm4freq=dB(S(2,2))=-14.084

1.300GHz

2 4 6 8 10 12 14 160 18

-10

-5

0

5

10

15

-15

20

freq, GHz

dB(S

(2,1

))

m2m2freq=dB(S(2,1))=15.035

1.300GHz

2 4 6 8 10 12 14 160 18

0123456789

-1

10

freq, GHz

Sta

bFac

t1

m5


400.0MHz


Optimized ATF-54143 Second Stage

MLINTL16


MLINTL12


MLINTL5


MLINTL6


SRLCSRLC5


MLINTL4


RR4R=100 Ohm

INDQL3

Rdc=0.0 OhmMode=proportional to freqF=100.0 MHzQ=50.0L=100 nH

SRLCSRLC7


RR8R=10 Ohm

SRLCSRLC8


MSTEPStep3


MLINTL17


SRLCSRLC12

C=10000 pFL=2 nHR=.3 Ohm

RR10R=10 Ohm

MLINTL14


SRLCSRLC11


MLINTL18

L=250 milW=10.0 milSubst="MSub1"

RR9R=50 Ohm

MLINTL15


MLINTL11


MSTEPStep1


VIA2V7


VIA2V8


VIA2V5


VIA2V6


S2PSNP2File="C:\S_DATA\FET\af541432d[1].s2p"

21

Ref


ATF-36077 cascaded with improved ATF-54143 Second Stage

SRLCSRLC5

C=1.65pFL=.25nH

R=.2Ohm

MLINTL11

L=100.0mil


MLINTL10

L=50.0mil


SRLCSRLC1

C=3.3pFL=.25nH

R=.2Ohm

SRLCSRLC4

C=1000pFL=1.4nHR=.3Ohm

MLINTL3

L=250milW=10.0milSubst="MSub1"

MSTEPStep2


MLINTL13


R

R3R=50Ohm

SRLCSRLC3


RR1R=50Ohm

SRLCSRLC2


MLINTL2


MLINTL1


RR2R=10Ohm

MLINTL8

L=50.0mil


MLINTL9

L=50.0mil


VIA2V4

W=25.0milRho=1.0T=0.7milH=31.0milD=15.0mil

VIA2V3


VIA2V2


VIA2V1


LL1

R=L=40nH

S2P

SNP1File="C:\S_DATA\FET\F360772A.S2P"

21

Ref

LL2

R=L=47nH

MLINTL16


MLINTL12


MLINTL5


MLINTL6


MLINTL4

L=500.0mil


RR4R=100Ohm

INDQL3

Rdc=0.0OhmMode=proportional to freqF=100.0MHzQ=50.0

L=100nH

SRLC

SRLC7


RR8R=10Ohm

SRLCSRLC8

C=6.8pFL=.25nH

R=.2Ohm

MSTEPStep3


MLINTL17


SRLCSRLC12

C=10000pFL=2nHR=.3Ohm

RR10R=10Ohm

MLINTL14

L=50.0mil


TermTerm2


SRLCSRLC11


MLINTL18


R

R9R=50Ohm

MLINTL15

L=50.0mil


MSTEPStep1

W2=100.0mil

W1=10.0milSubst="MSub1"

VIA2V7


VIA2V8


VIA2V5


VIA2V6


S2P

SNP2File="C:\S_DATA\FET\af541432d[1].s2p"

21

Ref

MSUBMSub1

Rough=0milTanD=.02T=.7mil

Hu=3.9e+034milCond=1.0E+50Mur=1Er=4.5H=31mil

MSub

TermTerm1



ATF-36077 cascaded with improved ATF-54143 Second Stage

1 20 3

0.51.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.0

5.0

freq, GHz

nf(2

)

m1

m1freq=nf(2)=0.359

1.300GHz

2 4 6 8 10 12 14 160 18

-30

-20

-10

0

-40

10

freq, GHz

dB(S

(1,1

))

m3

dB(S

(2,2

)) m4

m3freq=dB(S(1,1))=-4.904

1.300GHzm4freq=dB(S(2,2))=-12.991

1.300GHz

2 4 6 8 10 12 14 160 18

-20

0

20

-40

40

freq, GHz

dB(S

(2,1

))

m2

m2freq=dB(S(2,1))=37.878

1.300GHz

2 4 6 8 10 12 14 160 18

0123456789

-1

10

freq, GHz

Sta

bFac

t1

m5

m5freq=StabFact1=-0.202

1.590GHz

Still some concern about stability


ATF-36077 ATF-54143 Cascade with Further Improvements

MLINTL2

L=15.0milW=20.0mil

Subst="MSub1"

MLINTL1

L=15.0milW=20.0mil

Subst="MSub1"

SRLCSRLC5


R

R3R=100Ohm

RR2R=27Ohm

MSTEPStep1


MTEE_ADSTee2

W3=50.0milW2=20.0milW1=50.0milSubst="MSub1"

MLINTL4


INDQ

L3

Rdc=0.0Ohm

Mode=proportional to freqF=100.0MHzQ=50.0L=47nH

MLINTL21


SRLCSRLC7


RR4R=50Ohm

MLINTL11


MLINTL12


MLINTL5

L=45.0milW=20.0mil

Subst="MSub1"

MLINTL6

L=45.0milW=20.0mil

Subst="MSub1"

MLINTL3


MSTEPStep2


MLINTL13


SRLCSRLC4


MLINTL20


MTEE_ADSTee1

W3=50.0mil


MLINTL10


MLINTL9


MLINTL8


MLIN

TL19


RR1R=50Ohm

SRLCSRLC3


SRLCSRLC1


SRLCSRLC2

C=10.0pFL=.25nH

R=.2Ohm

VIA2

V4


H=31.0milD=15.0mil

VIA2

V3


H=31.0milD=15.0mil

VIA2

V2


H=31.0milD=15.0mil

VIA2

V1


H=31.0milD=15.0mil

LL1

R=

L=40nH


21

Ref

LL2

R=L=47nH

MLINTL16


RR8R=10Ohm

SRLCSRLC8


MSTEPStep3


MLINTL17

L=150.0mil


SRLCSRLC12

C=10000pFL=2nH

R=.3Ohm

R

R10R=10Ohm

MLINTL14


Term

Term2


SRLCSRLC11


MLINTL18


RR9R=50Ohm

MLINTL15


VIA2V7

W=25.0milRho=1.0

T=0.7milH=31.0milD=15.0mil

VIA2V8

W=25.0milRho=1.0


VIA2V5

W=25.0milRho=1.0


VIA2V6

W=25.0milRho=1.0


S2PSNP2File="C:\S_DATA\FET\af541432d[1].s2p"

21

Ref

MSUBMSub1

Rough=0milTanD=.02T=.7milHu=3.9e+034milCond=1.0E+50

Mur=1Er=4.5H=31mil

MSub

Term

Term1



ATF-36077 ATF-54143 Cascade with Further Improvements

1 20 3

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.0

5.0

freq, GHz

nf(2

)

m1

m1freq=nf(2)=0.377

1.300GHz

2 4 6 8 10 12 14 160 18

-20

-10

-30

0

freq, GHz

dB

(S(1

,1))

m3

dB

(S(2

,2))

m4

m3freq=dB(S(1,1))=-4.413

1.300GHzm4freq=dB(S(2,2))=-16.431

1.300GHz

2 4 6 8 10 12 14 160 18

-20

0

20

-40

40

freq, GHz

dB(S

(2,1

))

m2

m2freq=dB(S(2,1))=34.240

1.300GHz

2 4 6 8 10 12 14 160 18

0123

4567

89

-1

10

freq, GHz

Sta

bF

act1

m5m5freq=StabFact1=1.049

1.830GHz

At this point Rd = 27 ohms to get K=1 but NF .377. This is the best that can bedone with ATF-36077 driving ATF-54143….


What would make a better second stage?

Maybe a MMIC

The WLAN and WiMAX markets have forced semiconductormanufacturers to build sub 1 dB noise figure MMICs – thesemight make a good second stage but..

Most are in nasty little hard to see packages with no leadsexcept maybe the MGA-61563………


Effects of 2nd Stage

System NF with 13 dB gain 1st Stage

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.75

1.25 2

0.75

1.25 2

0.75

1.25 2

2nd Stage NF

dB NFs

0.60.60.60.50.50.50.40.40.4

1st NF


MGA-61563 Low Noise Amplifier

.01 uF

47 nH

47 pF

10

3V @ 43 mA

47 pF 47 pFMGA-61563

Input Output

1,2,5

63

4

510


MGA-61563 Measured Demo Board Performance

1 2 30 4

0.2

0.40.60.8

1.0

1.21.41.6

1.8

0.0

2.0

freq, GHz

nf(

2) m1

m2

m1freq=nf(2)=0.840

800.0MHzm2freq=nf(2)=1.250

3.500GHz

1 2 3 4 50 6

-30

-20

-10

-40

0

freq, GHz

dB(S

(1,1

))

m5 m6

dB(S

(2,2

))

m7

m8

m5freq=dB(S(1,1))=-9.629

800.0MHzm6freq=dB(S(1,1))=-8.164

3.500GHz

m7freq=dB(S(2,2))=-13.560

3.500GHzm8freq=dB(S(2,2))=-32.164

800.0MHz

1 2 3 4 50 6

5

10

15

20

0

25

freq, GHz

dB

(S(2

,1))

m3

m4

m3freq=dB(S(2,1))=20.411

800.0MHzm4freq=dB(S(2,1))=12.161

3.500GHz

1 2 3 4 50 6

0123456789

-1

10

freq, GHz

Sta

bF

act1

Not bad for a MMIC!


ADS Simulation with ATF-36077 MGA-61563 Cascade

m1freq=nf(2)=0.348

1.300GHz

1 20 3

0.5

1.0

1.52.0

2.5

3.03.5

4.0

4.5

0.0

5.0

freq, GHz

nf(2

)

m1

m1freq=nf(2)=0.348

1.300GHzm3freq=dB(S(1,1))=-5.586

1.300GHzm4freq=dB(S(2,2))=-18.873

1.300GHz

2 4 6 8 10 12 14 160 18

-30

-20

-10

-40

0

freq, GHz

dB

(S(1

,1))

m3

dB

(S(2

,2)) m4

m3freq=dB(S(1,1))=-5.586

1.300GHzm4freq=dB(S(2,2))=-18.873

1.300GHz

m2freq=dB(S(2,1))=39.296

1.300GHz

2 4 6 8 10 12 14 160 18

-20

0

20

40

-40

60

freq, GHz

dB(S

(2,1

))

m2 m2freq=dB(S(2,1))=39.296

1.300GHzm5freq=StabFact1=1.253

2.950GHz

2 4 6 8 10 12 14 160 18

0123456789

-1

10

freq, GHz

Sta

bFac

t1

m5


2.950GHz

I don’t believe K is a problem at 16 GHz but if it is a little Rd will help



1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.91.0 2.0

-30

-20

-10

-40

0

freq, GHz

dB(S

(1,1

))m6

dB(S

(2,2

)) m7

m6freq=dB(S(1,1))=-5.586

1.300GHzm7freq=dB(S(2,2))=-18.873

1.300GHz



RR2R=0Ohm

MLINTL2

L=15.0milW=20.0 milSubst="MSub1"

MLINTL1


RR3R=75Ohm INDQ

L4

Rdc=0.0 OhmMode=proportional to freqF=100.0 MHzQ=50.0L=22 nH

SRLCSRLC13

C=5.6 pFL=.25nHR=.2 Ohm

SRLCSRLC14

C=100 pFL=1.4nHR=.5 Ohm

SRLCSRLC15

C=10000pFL=1.4nHR=.5 Ohm

RR12R=10 Ohm

MLINTL25


MTEE_ADSTee3

W3=50.0 milW2=50.0 milW1=50.0 milSubst="MSub1"

MLINTL26


MLINTL24


TermTerm2


SRLCSRLC5

C=10 pFL=.25nHR=.2 Ohm

S2PSNP3File="C:\S_DATA\MGA-61563\m615633c[1].s2p"

21

Ref

MLINTL23

L=50.0 milW=50.0milSubst="MSub1"

MLINTL22


VIA2V10

W=25.0 milRho=1.0T=0.7milH=31.0 milD=15.0 mil

VIA2V9


MLINTL3

L=200 milW=10.0milSubst="MSub1"

MSTEPStep2


MLINTL13


SRLCSRLC4

C=1000pFL=1.4 nHR=.3Ohm

MLINTL20


MTEE_ADSTee1

W3=50.0 milW2=50.0 milW1=50.0 milSubst="MSub1"

MLINTL10


MLINTL9


MLINTL8


MLINTL19


RR1R=50Ohm

SRLCSRLC3


SRLCSRLC1


SRLCSRLC2


VIA2V4

W=25.0milRho=1.0T=0.7 milH=31.0 milD=15.0 mil

VIA2V3


VIA2V2


VIA2V1

W=25.0milRho=1.0T=0.7 milH=31.0 milD=15.0 mil

LL1

R=L=40 nH


21

Ref

LL2

R=L=47nH

MSUBMSub1

Rough=0 milTanD=.02T=.7milHu=3.9e+034milCond=1.0E+50Mur=1Er=4.5H=31 mil

MSub

TermTerm1


This is the approach taken for a new WD5AGO LNA


2 Stage ATF-36077 & MGA-61563 LNA


2 Stage ATF-36077 & MGA-61563 #1 Measured Results

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

-80

40

freq, GHz

dB(S

(2,1

))

m1

dB(S

(1,2

))m1freq=dB(S(2,1))=37.832

1.300GHz

2 4 6 8 10 12 14 16 180 20

-30

-20

-10

-40

0

freq, GHz

dB

(S(1

,1))

m2

dB

(S(2

,2))

m3

m2freq=dB(S(1,1))=-5.342

1.300GHzm3freq=dB(S(2,2))=-12.117

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Sta

bFac

t1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHzS

tabF

act1

m4


1.510GHz

NF measured 0.35 dB at 1296 MHz. K at low frequency erroneous due to lack of S12 dueto poor dynamic range in test equipment. Tough when LNA has 37 dB gain!


AP Note 1228 Single Stage ATF-36077 Measured Results

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

-80

20

freq, GHz

dB(S

(2,1

))

m1

dB(S

(1,2

))

m1freq=dB(S(2,1))=17.846

1.300GHz

2 4 6 8 10 12 14 16 180 20

-30

-20

-10

-40

0

freq, GHz

dB(S

(1,1

))

m2

dB(S

(2,2

)) m3

m2freq=dB(S(1,1))=-1.967

1.300GHzm3freq=dB(S(2,2))=-19.019

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Stab

Fact

1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHz

Sta

bFac

t1

m4


980.0MHz


2 Stage ATF-36077 & MGA-61563 in Enclosure

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

-80

40

freq, GHz

dB(S

(2,1

))

m1

dB(S

(1,2

))

m1freq=dB(S(2,1))=34.240

1.300GHz

2 4 6 8 10 12 14 16 180 20

-30

-20

-10

0

-40

10

freq, GHz

dB(S

(1,1

))

m2

dB(S

(2,2

))

m3

m2freq=dB(S(1,1))=-3.452

1.300GHzm3freq=dB(S(2,2))=-8.710

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Stab

Fact

1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHz

Sta

bFac

t1

m4


980.0MHz


2 Stage ATF-36077 & MGA-61563 in Enclosurewithout Lid

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

-80

40

freq, GHz

dB(S

(2,1

))m1

dB(S

(1,2

))

m1freq=dB(S(2,1))=34.841

1.300GHz

2 4 6 8 10 12 14 16 180 20

-20

-15

-10

-5

-25

0

freq, GHz

dB(S

(1,1

))

m2

dB(S

(2,2

))

m3

m2freq=dB(S(1,1))=-3.136

1.300GHzm3freq=dB(S(2,2))=-6.894

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Sta

bFac

t1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHz

Sta

bFac

t1

m4


980.0MHz


2 Stage ATF-36077 & MGA-61563 in Enclosure withMetal Divider Spanning Length of Box

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

-80

40

freq, GHz

dB

(S(2

,1))

m1

dB

(S(1

,2))

m1freq=dB(S(2,1))=33.545

1.300GHz

2 4 6 8 10 12 14 16 180 20

-40

-30

-20

-10

-50

0

freq, GHz

dB(S

(1,1

))

m2

dB(S

(2,2

))

m3

m2freq=dB(S(1,1))=-6.338

1.300GHzm3freq=dB(S(2,2))=-9.515

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Sta

bF

act1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHz

Sta

bFac

t1

m4


980.0MHz

Metal divider breaks up waveguide moding effect of box


Original 2 Stage LNA with ATF-36077 and ATF-21186

2 4 6 8 10 12 14 16 180 20

-60

-40

-20

0

20

-80

40

freq, GHz

dB(S

(2,1

))m1

dB(S

(1,2

))

m1freq=dB(S(2,1))=31.148

1.300GHz

2 4 6 8 10 12 14 16 180 20

-25

-20

-15

-10

-5

-30

0

freq, GHz

dB(S

(1,1

))

m2

dB(S

(2,2

))

m3

m2freq=dB(S(1,1))=-3.757

1.300GHzm3freq=dB(S(2,2))=-7.783

1.300GHz

2 4 6 8 10 12 14 16 180 20

0123456789

-1

10

freq, GHz

Stab

Fact

1

0.6 1.1 1.6 2.1 2.6 3.1 3.60.1 4.0

0

1

2

3

4

-1

5

freq, GHz

Stab

Fac

t1

m4


980.0MHz


13cm LNA Th - Tc

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

NE3210

84

ATF36

077

FHC40

NE3258

4

MGF4

953

MGF49

31

CFH800

ATF541

43

NF

dB

8

9

10

11

12

13

14

15

16

17

Gai

n

NF Th NF Tc G Th G Tc TH07


Summary

The MGA-61563 provided the additional gain desired whileproviding a lower noise higher IP3 second stage

LNA noise figures of 0.3 dB and 37 dB of associated gain havebeen demonstrated

Although the ATF-36077 / MGA-61563 cascade has beenshown to provide K greater than 1, the increased gain isproviding new challenges in enclosure design.

Any Questions?

designing stability into 1296 mhz and 2304 mhz low noise ... · using an atf-36077 followed by an...

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