dm_ch06

8/7/2019 dm_ch06

1/71

Monolithic RFIC Design

T.H.Huang

Reference books:

1. Thomas H. Lee, The Design of CMOS Radio-Frequency

Integrated Circuits, 2nd ed., Cambridge university press, 2004;

2. B. Razavi, RF Microelectronics, Prentice Hall PTR, 1998.

3. Frank Ellinger, Radio Frequency Integrated Circuits and Technology,

Springer-Verlag, 2006.

Part II. RF Circuit Design

8/7/2019 dm_ch06

2/71

Chapter 06

Low-Noise Amplifier Design

1. Introduction : different system applications

2. General Considerations : Noise, Noise match

Impedance (Power) match

3. Performance Evaluation Parameters : Gain,

Linearity,

Noise Figure,

Stability Factor

4. Introduction to LNA Topologies

8/7/2019 dm_ch06

3/71

RF Applications:

1. Cellular : (1G) : AMPS

(2G) : GSM, PCS, IS-54/IS-136 (NADC), IS-95(CDMA)

(2.5G) : GPRS / EDGE (2.5G)

(3G) : W-CDMA

(4G): http://zh.wikipedia.org/wiki/4G

2. Non-Cellular : WLAN, Bluetooth, WPAN, UWB, WBN

GPRS : General Packet Radio Service

EDGE : Enhanced Data Rates for GSM Evolution
http://zh.wikipedia.org/wiki/4Ghttp://zh.wikipedia.org/wiki/4G

8/7/2019 dm_ch06

4/71

Some Characteristics of AMPS: (Analog-type)

Parameter Value

Advanced Mobile Phone Service (AMPS)

Mobile-to-Base Frequency

Base-to-Mobile Frequency

Channel Spacing

Multiple access method

Duplex MethodUsers per channel

Modulation Methodology

824-849 MHz

869-894 MHz

30 kHz

FDMA

FDD1

FM

FDD:using different

frequencies for

transmitting &

receiving.

8/7/2019 dm_ch06

5/71

Some Characteristics of GSM-900: (Digital-type)

Parameter Value

Global System for Mobile Communications (GSM-900)



Channel Spacing




Channel bit rate

880-915 MHz

925-960 MHz

200 kHz

TDMA/FDM

FDD8

GMSK; BT=0.3

270.833 kb/s

B:

filters bandwidth.

T:

bit period (time).

8/7/2019 dm_ch06

6/71

Some Characteristics of GSM-1800:

Parameter Value

Global System for Mobile Communications (GSM-1800)



Channel Spacing




Channel bit rate

1710-1785 MHz

1805-1880 MHz

200 kHz

TDMA/FDM

FDD8

GMSK; BT=0.3

270.833 kb/s

Only freq.

as comparedwith GSM-900.

8/7/2019 dm_ch06

7/71

Some Characteristics of PCS-1900: (in USA)

Parameter Value

Personal Communication System (PCS-1900)

Mobile-to-base Frequency


Channel Spacing




Channel bit rate

1850-1910 MHz

1930-1990 MHz

200 kHz

TDMA/FDM

FDD8

GMSK; BT=0.3

270.833 kb/s

8/7/2019 dm_ch06

8/71

Some Characteristics of IS-54/-136:

Parameter Value

North American Digital Cellular (NADC; IS-54/-136)



Channel Spacing / Numbers




Channel bit rate

824-849 / 1850-1910 MHz

869-894 / 1930-1990 MHz

30 kHz / 832 / 1999

TDMA/FDM

FDD3

/4-DQPSK

48.6 kb/s

8/7/2019 dm_ch06

9/71

Some Characteristics of IS-95 CDMA: (by Qualcomm. Corp.)

Parameter Value

Code Division Multiple Access (CDMA)



Channel Spacing / Number


Duplex Method

Users per channel


Channel bit rate (chip rate)

*(see below)

*(see below)

1250 kHz / 20 / 48 / 48

CDMA / FDM

FDD

15 - ?

QPSK / OQPSK

1.2288 Mb/s

8/7/2019 dm_ch06

10/71

CDMA Operation Frequencies:

800 MHz 1900 MHz Asia (*)

__________________________________________

Mobile-to-base

Base-to-mobile

824 849

869 894

1850 1910

1930 1990

1920 1980

2110 2170

* For example:

Japan : DoCoMoKorea : Samsung

8/7/2019 dm_ch06

11/71

Requirements of 3G (W-CDMA, CDMA-2000, UMTS):

high-speed digital communication, not voice-centric;

144 kb/s in-vehicle data rates (a moving car);

Up to 384 kb/s for pedestrians (a walker);

Other issues like what in 2G CDMA.

The next generation 4G:

Using W-OFDM modulation methodology;

Higher data rates then W-CDMA.

http://zh.wikipedia.org/wiki/4G
http://zh.wikipedia.org/wiki/4Ghttp://zh.wikipedia.org/wiki/4G

8/7/2019 dm_ch06

12/71

Summary of IEEE 802.11b/a/g:

Parameter

Wireless Local Area Network (WLAN)

Operation Frequency

Channel Spacing


Duplex Method


bit rate (or symbol rate)

802.11 b 802.11 g 802.11 a

2400-2483.5MHz5150-5350 MHz

5725-5825 MHz

FHSS: 1MHz

DSSS: 25MHz OFDM: 20 MHz

Channel Numbers 3 non-overlapping 12 non-overlapping

CSMA / CA

TDD

FHSS: GFSK,

BT=0.5

OFDM: 64-QAM for 54 Mb/s

1,2, 11 Mb/s 54 Mb/s12 Ms/s

5.5-54 Mb/s

8/7/2019 dm_ch06

13/71

Summary of Bluetooth:

Parameter Value

Bluetooth

Frequency Range

Channel Spacing / Number


Duplex Method

Users per channel


Symbol rate

2402 2480 MHz

1 MHz / 79

Frequency Hop

TDD

200 (7 active)

GFSK

1 MS/s

8/7/2019 dm_ch06

14/71

Summary of IEEE 802.15.4 (ZigBee):

Parameter Value

Wireless Personal Area Network (WPAN) -- ZigBee

Frequency range (USA)

Channel Spacing


Duplex Method

Users per channel


Peak bit rate

2402 2480 MHz / 902-928 MHz

5 MHz

CSMA / CA / CD / TDMA

FDD

255

OQPSK / GFSK / BT=0.5

250 / 40 / 250 kb/s

Frequency range (Europe) 2412-2472 MHz

CSMA : Carrier Sense

CA : Collision Avoidance

CD : Collision Detection

8/7/2019 dm_ch06

15/71

Ultra-Wide Band (UWB): from 3,168 MHz 10,560 MHz

Definitions:

( )( )

GHz2.5frequencyoperationasMHz500BW3.

G1.5rangetuningandGHz;6frequencyoperation2.

0.2);(or0.25ffff2BWfractional1.LH

LH

>>

>>

+

=

DS-CDMA :

MB-OFDM :

8/7/2019 dm_ch06

16/71

Low Noise Amplifier:

Commonly, the first stage of a receiver for any system

The requirement of low noise and high gain

in the first stage:

( )( ) ( ) ( )

too.dB),in(notlinearingainpowertheisG

stage,th-mtheofdB)in(notlinearinfactornoisetheis

equation)(Friis111

11F

:StagesCascaded-mofFigureNoise

n

1

21

3

1

21total

m

n

m

n

m

F

where

G

F

GG

F

G

FF

=

++

+

++=

Noise

8/7/2019 dm_ch06

17/71

Cascaded Nonlinear Stages:

( ) ( ) ( ) 22

2

1

1

22

2

111

3

3

122113

2

3

3

122113

11

3

3

3

122113112

3

13

2

12112

3

3

2

211

IIP3

2

3

IIP3

1

2

4

3

IIP3

1

aboutisIIP3case,-worstThe

P.63)LecturedB,in(not)2(

3

4IIP3

(t))x2(x(t)(t)y

(t)y(t)y(t)y(t)y

(t)x(t)xx(t)(t)yLet

cascade.instagesnonlinearwoConsider t

++=++

++=

++++=

+++=

+++=

Linearity

(to next stage)

8/7/2019 dm_ch06

18/71

Cascaded Nonlinear Stages: (cont.)

( ) ( ) ( ) ( ) ( )

( ) ( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

gain.stageth-nthe

ofdB)in(notgain(voltage)linearthe,:

IIP3IIP3IIP3IIP3

1

IIP3IIP3IIP3IIP3

1

IIP3

1

:stagecascade-na,

IIP3IIP3

1

IIP32

3

IIP3

1

IIP3

1

:isstagescascadedtwoaforIIP3case,-worst

2111

2

21

22

21

23

22

21

22

21

21

2

21

21

23

21

21

22

21

21

2

22

21

21

22

21

1

2221

2

areGGNote

GGGGGG

forSimilarly

The

n

n

ntotal

==

++++=

++++

+++

8/7/2019 dm_ch06

19/71

Brief Summary:

LNA: trade-offs between Gain, Noise, and Linearity

For noise consideration :

The first stage must be high gain and less noise

to achieve the overall low-noise performance;

For linearity consideration :

The latest stage must be with high IIP3 to

achieve the overall better linearity performance.

8/7/2019 dm_ch06

20/71

8/7/2019 dm_ch06

21/71

8/7/2019 dm_ch06

22/71

Power match:

Conjugate match:

Maximum power translation:

.RR@P2

1P0)(

1

2

1

22)(

SLSmaxin,

2

222

===

+=+

+=

+

==

Lin

L

LS

L

SLS

L

LS

S

LS

L

L

S

L

inLin

RPR

RR

R

PRR

R

RR

V

RR

R

R

V

R

VRP

slation)power tran(maximum

*

SSinS

SSSin

SSS

RRZZ

jXRZZ

jXRZ

+=+

==

+=

Rs

RL

+

-

Vs

Vin

ZinZs

Typically, inputmatch = 50 for LNA,

because of filter or

antenna.

8/7/2019 dm_ch06

23/71

Input match for CS amplifier

> Rs : the signal source resistance;

> Let R1 (equivalent bias R) 50 > Adding R1, Thermal noise

Input signal power (V-swing) @ gate

> In general, noise figure degrades.

But recall the noise circle vs. gain

circlebehavior maybe cause abetter noise figure overall.

(impedance dependent noise match)

Typically, the lower bound on the noise of this circuit:

RRRwhereRg

1

42FFigure,Noise 1s

m

==+

8/7/2019 dm_ch06

24/71

1. Broadband real input impedance;

2. Better than the amplifier (Fig.11.1)

in noise figure, because of

no signal degrade at gate terminal.

(using self-bias, V-swing can be

greater.)

3. In UWB application*. (conceptive)

Input match for CS amplifier using negative feedback:

8/7/2019 dm_ch06

25/71

8/7/2019 dm_ch06

26/71

Summary of Different Types of Amplifiers:

Types of Amplifiers Rin Rout (Voltage) Gain

______________________________________________

CS

CG

CD

High

Low

Medium

High

Medium

Low

High

Low

Low

8/7/2019 dm_ch06

27/71

Feedback Configurations:

Negative Feedback Features:

1. Desensitize the gain : ex. temperature effect.

2. Reduce nonlinear distortion : degeneration, gain constant.

3. Reduce the effect of noise : extra mechanism to compensate noise.

4. Control the input and output impedance : to correlate the I/O resistances.

5. Extend the bandwidth of the amplifier.

8/7/2019 dm_ch06

28/71

ns/VVS/N =

[ : LNA]Noise reduction using negative feedback:

(LNA, betterif noiseless)

2n

s

21

1n21

21so

AV

V

N

S

AA1AV

AA1AAVV

=

+++=

8/7/2019 dm_ch06

29/71

Summary of Four Basic Feedback Configurations:

Rin Rout

Voltage Amp.

Trans-G Amp.

Trans-R Amp.

Current Amp.

Input

(Mixing)

Output

(Sensing)

series shunt

series series

shunt shunt

shunt series

Increase / decrease factor : A+ 1

Input Output

iV

iV

iI

iI

oV

oI

oI

oV

8/7/2019 dm_ch06

30/71

A reason of resistive component arising from the gate capacitance:

Question: Why the input impedance of a MOSFET has a

resistance component from the AC viewpoint?

(gate-to-drain cap.)

[ ] [ ]

[ ]

resistoralikebehavepartrealapossesses

)(YImj)YRe(

)sin(cos11

)sin(cos1

1

1

1

AA(s)shift,phaseandgainhaveA(s)

EffectMiller)](1[

1

0

00

0

+=

+==

+=

+=

=

+

=

inin

in

in

jin

j

in

jACjZ

Y

jACjeACjZ

then

eif

sAsCZ

8/7/2019 dm_ch06

31/71

Input impedance due to the source degeneration:

Z

( )[ ]

[ ]Ze1Cj

1

Zj1Cj

1Z

)t(j0

gs

gsin

+++=

++=

1. Capacitive degeneration

becomes a negative resistance

2. Inductive degeneration

becomes a positive resistance.

8/7/2019 dm_ch06

32/71

8/7/2019 dm_ch06

33/71

Brief Summary:

1. Impedance match can be done by source degeneration;

2. This converted resistance brings no thermal noise,

because it is not a real resistor! (very important!)

3. No extra thermal noise is introduced;

4. To utilize this method to do either power match or

noise match, or even both.

5. However, this is a narrow band matching.

[to be continued]

8/7/2019 dm_ch06

34/71

Intrinsic MOSFET Two-Port Noise Parameters:

channel)-longforn,(assumptio395.0ii

iic

astcoefficienncorrelatioawith

noise,drainwith thecorrelatedisnoisegatethe

)(5

4

4

2

nd

2

ng

*

ndng

22

2

2

j

there

fittingfromgCg

where

fgkTi

fgkTi

do

gs

g

gng

dond

=

=

=

(*ref[1], Ch12.2)

(drain current noise)

(gate current noise)

8/7/2019 dm_ch06

35/71

Four equivalent two-port noise parameters:

correlatede

iYwhereYB

YG

eduncorrelat

fkT

iG

g

g

fkT

e

fg

gkT

g

ie

n

cccc

cc

uu

m

don

m

do

m

ndn

=

==

]Im[

]Re[4

4R

:parametersnoisefour.2

4

:noisecurrentdrainreferredinput.1

2

2

2

n

22

22

8/7/2019 dm_ch06

36/71

Open-Circuit Drain Current Noise:

nd

mngcge

n

ngc

gs

n

ngcn

n

m

nd

m

ndopenn

i

giCj

e

iCj

e

ii

eg

i

g

ie

+=+=+

=

==

==

1

c

ngu

ngc

2

gs

2

2

2gs

22

n1

2

22

,2

gs

2

n1

Y

:admittancecorrelatedThe3.

noise.currentdrainth thecurrent wigateeduncorrelatfullythei

noise.currentdrainth thecurrent wigatecorrelatedfullythei

terms,twoofconsistsitselfcurrentnoisegateinducedThe.2

)C(j)C(j

i

)C(j

i

.capacitivepurelyis

MOSFETaofadmittanceinputthat theAssumed.1

8/7/2019 dm_ch06

37/71

1)channel,-long(for1

)5

1(5

isc5

5

Y

2

22

2

2

2

2

22

*

2

2

22

*

2

2

2

*

*

*

c

==

=+=

+=

+=+=

+=

+=

+=

+=

+=

do

m

gsgs

do

mgs

gs

do

mgs

do

gs

mgs

nd

ng

mgs

nd

ng

ndng

ndngc

mgs

ng

ng

ndnd

ndngc

mgs

ng

ng

nd

ndngc

mgs

ndnd

ndngc

mgs

nd

mngcgs

g

gwhere

cCjCcg

gjCj

cjassumedCcg

gCj

g

CcgCj

i

icgCj

i

i

ii

iigCj

i

i

ii

iigCj

i

i

i

iigCj

ii

iigCj

i

giCj

( )

8/7/2019 dm_ch06

38/71

1. Since Yc (the correlation admittance) is pure imaginary,

so that Gc = 0. (assumption in this modeling case)

2. The induced gate noise :

)1(44)(2222 cfgkTcfgkTiii gggnungcng +=+=

(correlated) (uncorrelated)

3. The uncorrelated portion of the gate noise current makes

do

gsguu

g

cC

fkT

cfgkT

fkTiG

5

)1(

4

)1(4

4

22222 =

=

4. To achieve the minimum noise figure Bopt = -Bc = -Im[Yc]

8/7/2019 dm_ch06

39/71

5. Bopt is negative, it means that the optimum source susceptance

is essentially inductive in character.

6. The real part of the optimum source admittance is:

2

2

222 ,)1(

5

u

n

u

n

ugsc

n

uopt G

e

i

R

GwherecCG

R

GG ===+=

7. The minimum noise figure is given by:

.

)1(5

2

1][212

min

gs

mT

T

coptn

C

gwhere

cGGRF

=

+++=

* As T , Fmin

*Ways to minimum

the Fmin by

8/7/2019 dm_ch06

40/71

8/7/2019 dm_ch06

41/71

8/7/2019 dm_ch06

42/71

8/7/2019 dm_ch06

43/71

1. Two replica devices under the same bias condition;

2. Using current-controlled current source (CCCS) to introducethe noisy drain current into the gate circuits of those

replica devices;

3. Using voltage-controlled voltage sources (VCVS) to ensure

the same bias conditions;

4. Each replica possesses a provision for feeding back

its own noisy drain current to its own gate node.

5. Summation of the two noise (and fully uncorrelated)

currents there results in a noisy voltage at the gate

of M2 (or at M3 with the similar expression):

.gchannel,long

)(84

2

do

2

3

2

2

m

g

mdo

g

gfor

vg

fkT

g

fkTv

==Combined

M1s and M2s

noises.

8/7/2019 dm_ch06

44/71

6. The noisy gate voltage causes to flow a noisy gate current

of mean-square value:

>

8/7/2019 dm_ch06

45/71

9. After subtraction, the difference current must be scaled

appropriately to produce the correct noise current levelof

> NF of single-end

3. For equal NF :

Power of differential ~ 2 x Power of single-end

4. Common-mode noise rejection by differential configuration.

8/7/2019 dm_ch06

57/71

Design Examples:

A Simple Differential LNA:

8/7/2019 dm_ch06

58/71

Design Examples: (cont.)

Source degenerator

(matching, linearity

enhancement)

Current re-use

for the core and

the buffer stage.

Coupled cap.

for buffer inputs.

Inductive loadsof amplifier

A start-up

transistor

A Complicated Differential LNA:

Note: keep all transistors

operated in saturation!!

With a

common-mode

bias feedback loop.

8/7/2019 dm_ch06

59/71

Linearity and Large-Signal Performance:

LNA must maintain linear operation when

as receiving a weak signal, and

as in the presence of a strong interfering signal.

(large dynamic range)

Desensitization (orblocking) :

signal (small) + interference (large)

Cross-modulation:

signal (small) + interference (large and modulated)

(distortion due to the large voltage swing)

8/7/2019 dm_ch06

60/71

Desensitization ( Blocking):

>

8/7/2019 dm_ch06

61/71

Cross Modulation:

modulated!isamplitutethewhere

cos)]cos22cos22

1(2

3[)(

cos)cos1(cos)(

)()()()(

1

22221311

21

2211

33

221

+++++=

8/7/2019 dm_ch06

62/71

Nonlinearity : (intermodulation phenomenon, two-tone test)

)]cos(3)[cos(3]4

[

)]cos(2)[cos(2]2

[

)]cos()[cos(]4

9Ac[

]c[v)i(V

havewe),i(back tov

)]cos()A[cos(v

test)tone-(Twofrequencydifferentslightlybut

amplitudeequalofsignalsinputsinusoidalwoConsider tvcvcvccv)i(VLet

21

33

21

22

213

31

220DC

21

33

2210DC

ttAc

ttAc

ttAc

Ac

ngSubstituti

tt

++

++

+++

++

+=

++++

DC

Fundamental

Double-freq.

Triple-freq.

>

8/7/2019 dm_ch06

63/71

])cos(2)cos(2)2cos()2[cos(]4

3

[

])cos()[cos(]2

[v)i(V

havealsowe),i(back tov

)]cos()A[cos(v

test)tone-(Twofrequencydifferentslightlybut

amplitudeequalofsignalsinputsinusoidalwoConsider t

vcvcvccv)i(VLet

21212121

3

3

2121

22

DC

21

33

2210DC

ttttAc

ttAc

ngSubstituti

tt

++++++

++++

+=

++++

Nonlinearity : (cont.)

>

8/7/2019 dm_ch06

64/71

Input-referred third-order interception point (IIP3):

ss Rc

c

R

AIIP

squarevoltageA

c

cAAcAc

Let

1

3

2

23

3

4

4

3

3

12

2

3

12331

==

=

==

8/7/2019 dm_ch06

65/71

Pout plotted with Power measurement:

3rd order

Intercept

Input power

(dB)

Output power

(dB) P1dB

Slope = 3

Slope = 1

10~15 dB

IIP3

8/7/2019 dm_ch06

66/71

Methods for Estimating IP3:

Simulation with tools either by

transient simulation FFT Pout vs. Pin plot

harmonic balance simulation (frequency domain)

Two-tone testing:

with a spectrum to read out the power levels of

inter-modulation terms.

Three-point method: (by DC+0, V)

see below.

8/7/2019 dm_ch06

67/71

IIP3 vs. Gain:

+

=

+=++=

=

++=

)0(2)()(

)0(43

32)(

32)(

)0(

32cg(v)

isg(v)uctancetranscondthe

2

2321

2321

1

2321

gVgVg

g

R

VIIP

VcVccVg

VcVccVg

cg

vcvc

Let

s

8/7/2019 dm_ch06

68/71

Bias dependent IP3:

There is a sweet point of lowest IIP3 with different

bias current for a transistor.

In the narrowband LNA architecture, the input voltage is multiplied

by the Q of the input circuit before appearing between gate and

source. Hence,

+= )0(2)()()0(43 2

2

gVdgVgg

RQVIIP

ss

8/7/2019 dm_ch06

69/71

Improvement of Linearity by a pair of parallel transistors:

M1 M2RFIN RFIN

RFOUT

8/7/2019 dm_ch06

70/71

Spurious-free dynamic range (SFDR):

Definition: the signal-to-noise ratio corresponding to the inputamplitude at which an undesired product (here, the third-order

IM power) just equals the noise power.

Input power

(dB)

Output power

(dB)

Slope = 3

Slope = 1

Output

Noise level

SFDR

8/7/2019 dm_ch06

71/71

dm_ch06

Documents

Transcript of dm_ch06