GaN Low Noise Broadband Amplifiers and Technology

WFE: Gallium Nitride for Low Noise Amplifier Applications

Kevin W. Kobayashi, RFMD

Mike Wojtowicz, Northrop Grumman

Outline

• Low Noise GaN HEMT Technology

• Device Design

• NF characteristics- NG

• Survivability

• Trends in Literature

• Broadband S-/C-band LNA Design

• Wide-band Linear Applications

• Design Topology Trades

• Linear Cascode LNA example

• Technology Comparison of LNA NF-IP3

• CATV Example

• Future Trends in GaN LNAs

Materials Outline

• Why GaN?

• Intrinsic noise sources in GaN HEMTs

• Back barrier design

• Bias impact to NFmin

• Gate size impact to NFmin

• Material profile impact to NFmin

• Summary

Why GaN LNA?

• NF similar to GaAs HEMT

• 10-15 dB increase in power

surge survivability

• No need for protection

circuit

• Simplifies transceiver

design

• Improves spurious-free

dynamic range (SFDR)

GaN

GaAs

InP

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30 40 50 60

Vds (V)

Pu

lsed

Id

s (

A/m

m) GaN HEMT Pulsed IV GaNGaN

GaAsGaAs

InP

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30 40 50 60

Vds (V)

Pu

lsed

Id

s (

A/m

m) GaN HEMT Pulsed IV

GaN HEMT simplifies receiver front-end electronics

Survivability

• GaN LNAs provide >30 dBm overdrive survivability

Frequency

(GHz)

Gain

(dB)

Noise Figure

(dB)

Survivability

(dBm)

Reference

3.5 – 7.0 20 2.3 33.0 [4-1]

10 12 0.8 31.6 [4-2]

1 - 8 16 2.0 38.0 [4-3]

4.5 - 16 10 2.5 37.3 [4-4]

0.6 – 5.0 10.1 3.0 30.0 [4-5]

2 - 12 9 3.0 36.0 [4-6]

4 – 6.5 10 1.9 31.0 [4-7]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 10 20 30 40 50 60 70

Nfm

in (d

B)

Frequency (GHz)

GaN HEMT

GaAs pHEMT

InP pHEMT

Noise Comparison

• GaN provides equivalent noise to 0.1um GaAs pHEMT

[5-1]

[5-1]

[5-2]

[5-3] [5-1]

[5-4]

[5-5] [5-6]

Noise Sources

• Four primary intrinsic sources of noise in

AlGaN/GaN HEMTs [6-1], [6-2]

• Velocity fluctuation of channel electrons due

to scattering

• Heterojunction interface

• Lattice (phonon)

• Impurities

• Frequency independent

• Vg fluctuations

• Highly correlated to Id fluctuations in channel

• Frequency independent

• Gate leakage due to injection of electrons into

the channel

• Random process

• Results in shot noise

• Electron trapping

• Surface states

• Interface states

• Bulk defects

• 1/f

Back-barrier

GaN Channel

AlGaN Schottky

Gate Source Drain

SiN

SiC

Le

aka

ge

- Traps

- Velocity

Fluctuation

AlN Insert

Vg

Back Barrier Profiles

AlxGa1-xN Schottky Barrier

GaN Buffer

AlxGa1-xN Schottky Barrier

GaN Channel

AlxGa1-xN buffer

GaN Buffer

AlGaN Back-barrier

• Double heterostructure profiles

provide enhanced carrier

confinement

• Mitigate velocity fluctuations

-4

-3

-2

-1

0

1

2

0 200 400 600 800

En

ergy (eV

)

Thickness (Ang.)

Conduction Band

Valence Band

GaN buffer

AlGaN back-barrier

1-D Poisson Simulations

Double Heterostructures

• Double Heterostructures reduce short channel effects for Lg < 0.25um

• Improves pinch-off

• Reduces sub-threshold leakage

• Good pinch-off necessary for low noise performance

GaN Back-Barrier

GaN Back-Barrier

AlGaN Back-Barrier

10-5

10-3

10-1

101

103

Noise vs Bias

• NFmin decreases with Id and increases slowly with Vd

• Dominated by channel velocity fluctuations

• Able to maintain low NFmin over wide drain bias condition

• Minimum NFmin at 100mA/mm (75% Idsp) and 2.5 – 5.0V

10 GHz NFmin/Ga Contours

0.2um Lg, 4f200um device

AlGaN back-barrier

0.1um InP pHEMT optimal bias

0.5 – 1 V Vds, 100mA/mm

0.1um GaAs pHEMT optimal bias

2V Vds, 100mA/mm

0.2um GaN pHEMT optimal bias

4V Vds, 100mA/mm

0.4

Noise vs Gate Length

• NFmin is constant against gate size for a constant gain and gate

leakage

• Smaller gate lengths improve NFmin at higher frequencies

0.2um Lg w/ AlN 0.2um Lg w/ AlN

0.1um Lg w/ AlN 0.1um Lg w/ AlN

5V-100mA/mm, 4f200um device

AlN Insert, AlGaN back-barrier

NFmin = 1 + K 2 p f Cgs

√ gm √ Rg + Rs

Noise vs. Gate Leakage

• NFmin is expected to increase rapidly with Ig (~0.5dB for 10x

increase in Ig) [10-1]

0.2um Lg

0.25um Lg

0.2um Lg

0.25um Lg

0.25um: Ig ~1x10-3 mA/mm

0.2um: Ig ~1x10-4 mA/mm

~ 10X difference in Ig

5V-150mA/mm, 4f200um device

AlGaN back-barrier

10-4

10-3

10-2

10-1

100

10-5

Noise vs AlN Insert

• AlN insert layers reduce Rsh

• Does not impact NFmin at best noise bias [12-1]

0.2um Lg w/o AlN

0.2um Lg w/ AlN 0.2um Lg w/ AlN

0.2um Lg w/o AlN

Imax Rsh

0.2um w/o AlN 0.96 A/mm 471

0.2um w/ AlN 1.1 A/mm 366

5V-100mA/mm, 4f200um device

AlGaN back-barrier

Noise vs Back-Barrier

• NFmin degrades with poor channel confinement

10GHz NFmin Contour

0.25um Lg, GaN Back-Barrier 10GHz NFmin Contour

0.25um Lg, AlGaN Back-Barrier

GaN Back-barrier

AlGaN Back-Barrier

10-5

10-3

10-1

101

103

Materials Summary

• GaN HEMTs provide similar NFmin to GaAs HEMTs and

provide >30dBm survivability

• Eliminates need for protection diodes resulting in overall

system noise reduction

• Key noise sources consistent with other HEMT devices

• Primary contributor to NFmin is gate leakage and poor

channel confinement

GaN LNA Motivation

•GaN LNA Motivations • Survivability

• Combination of Low NF- High Linearity

• Wide BW (decade/octave)

•Enables Future Applications • Software defined Radios

• Higher Spectral Efficient P2P

• RF on Fiber

• Extended CATV

Bandwidth

Sensitivity

(Low NF)

Linearity

Power/Efficiency

SDR Radios

Network Reach

> Decade BW

CATV

Multi-carrier

Multi-mode/format

GaN Front-End Multi-Octave BW Infrastructure Systems

0

0.5

1

1.5

2

2.5

3

3.5

4

0 2 4 6 8

Nois

e F

igure

(dB

)

Frequency (GHz)

State-of-the-Art GaN MMIC Noise Figure

[6] SIRENZA-NG

[3] NG

[4] NG

[1] HRL

[2] UCSB

[5]NG [9] NG

2011 CSIC [14]

Cascode LNA

8-Watt

[11]

[10]

[7] RFMD-NG, T= -10C

CS-LNA

2-Watt

< 1 Watt

Dual-gate

FB LNA

Broadband Linear-Low Noise Topology Considerations

Common-Source

Best NF

Ls-optimum Gopt-S11

Gain slope

WHY?

Darlington FB

Widest IP3-BW

Decade Gain-BW

Limited NF

WHY?

Distributed Amp

Widest Gain-BW

High Power-BW

Limited LF NF

WHY?

Cascode FB

Wide Flat Gain-BW

Good NF

Good IP3/IP2

Poor PAE

2007 RFIC

2011 CSIC

2008 CSIC

Noise contribution due to

unity gain of transistor M1.

Soln. Pre-Amp.

Noise contribution due to

Input termination resistor in

shunt with input. Soln. Active load? 2009 RFIC

Gain roll-off due to source

Inductance degeneration.

Soln. Use gate inductance.

Common-gate increase I-V

knee voltage and reduces

dynamic voltage swing.

OUT

IN

LchokeVdd = 15V

Cbypass

Idd

0.2um x 50um

x 24

Rfb

Rg

Ls

Cfb

Vgs

OUT

IN

Rfb

Rg

Vg1

MC M1

M2

MC

Rdc

Rfb

Cfb

Rs

Cbyp

Rout

Rin

Cout

Cin

TLin1

Cg2 Cg2 Cg2 Cg2

Vg1

Vg2

OUT

IN

Cg2_ext

Cin_ext

Cout_ext

M1_cs M2_csM8_cs

M9_cs

M1_cg M2_cg M8_cg M9_cg

TLin2 TLin8 TLin9 TLin

TLout1 TLout2 TLout8 TLout9 TLout

. . .

. . .

. . .

Common-Source vs. Cascode

Performance

Common-

source

Cascode/*Dual

gate

Practical Vdd 20V (T-gate) 40V

Pout , IP3 4-6 dB improvement

Idd 250mA/mm same

Tj @ 85C

base

~200C ~*200C

NF higher (id1_n,id2_n)

BW much wider

Gain much higher, flatter

Stability poorer

Cascode Characteristics

10 20 30 40 50 60 70 80 90 0 100

10

20

30

40

0

50

Frequency (GHz)

CASCODE

COMMON-SOURCE

Ma

x G

ain

(d

B)

Wg = 500um HEMT

Maximum Available Gain I-V characteristics

10 20 30 40 50 60 70 0 80

0.2

0.4

0.6

0.8

1.0

0.0

1.2

VDS

COMMON-SOURCE CASCODE

A/mm

IDS

(A

/mm

)

Cascode has higher MAG Cascode has higher Ro, good IP3

But higher Vknee, poorer PAE

*Tj~200C @ 20V-250mA/mm

Device Noise Characteristics

freq (500.0MHz to 3.000GHz)N

PA

R_

Wg

_6

00

um

_2

50

mA

pe

rmm

..S

op

tN

PA

R_

Wg

_1

mm

_2

50

mA

pe

rmm

..S

op

tN

PA

R_

Wg

_2

mm

_2

50

mA

pe

rmm

..S

op

tN

PA

R_

Wg

_3

mm

_2

50

mA

pe

rmm

..S

op

t

Gopt

Wg = 3 mm

2 mm

1 mm

0.6 mm

NFmin ~ 0.65 dB @ 2 GHz

0.0

0.5

1.0

1.5

0 2 4 6 8 10

NF

min

(dB

)

Frequency (GHz)

4F200um Vds = 15V

50 mA/mm

100 mA/mm

150 mA/mm

250 mA/mm

300 mA/mm

IP3-Noise-match trade

•Wg =3mm IP3 > 50dBm

•Wg ~1mm better 50-ohm noise match

GaN Cascode Feedback Design Optimized for IP3-BW

Chip size is 1.6x1.3 mm2 GaN Cascode Feedback LNA

• Cascode

• Wg_total = 3 mm

• Vdd = 40V

• Idd = 500-750mA

4 finger x 125um

(Wg=500um unit cell)

Cascode Gain & NF Performance

-40

-30

-20

-10

0

10

20

30

0 1 2 3

Ga

in &

Re

turn

-Lo

ss (d

B)

Frequency (GHz)

40V-750mA

S21

S11

S22

2.92.4 2.3

2.5 2.53.0 2.9

3.6

3.02.7 2.7

3.0 3.2

3.8 3.7

4.6

0

1

2

3

4

5

6

0 1 2 3 4

No

ise

Fig

ure

(d

B)

Frequency (GHz)

40V-750 mA

40V-500 mA

S-parameters

• Gain 20dB

• BW ~ 250MHz -3 GHz

• LF Gain limited to on-chip Cap

Noise Figure

• 2.3-3.0dB @ 40V-500mA

• 2.7-3.8dB @ 40V-750mA

• Not as Low as predicted! WHY?

Simple Noise Contribution Calculation

CALCULATED

0

1

2

3

4

5

6

0 1 2 3 4

Nois

e F

igure

(dB

)

Frequency (GHz)

0

1

2

3

4

5

6

0 1 2 3 4

Nois

e F

igure

(dB

)

Frequency (GHz)

MEASURED

Channel Thermal Noise

4KT G(1/gm)

FB Resistor

Rg+Ri+Rs

Fukui

Equation

MEASURED

Channel Thermal Noise

4KT G(1/gm)

FB Resistor

Rg+Ri+Rs

Fukui

Equation

CALCULATED

MEASURED

Cascode LNA Linearity

54.352.7 53.3 51.9 51.8 51.4 50.8 52.0

50.748.6

50.248.4

50.048.0 48.0 48.4

20

30

40

50

60

0 1 2 3 4

OIP

3 (d

Bm

)

Frequency (GHz)

40V-750 mA

40V-500 mA

GaN

D-PHEMT

HFET

HBT-WB [14]

[5]

[7]

[6]

[3]

[10]

[1]

[12-13]

HBT-NB

NB= Narrow band tuned

WB= Wide band tuned

[14]

[2012 RFIC]

E-PHEMT

IP3-NF Technology Comparison

25

30

35

40

45

50

55

0 1 2 3 4 5 6 7 8

OIP

3 (d

Bm

)

Noise Figure (dB)

Summary of S-band LNA & Gain Block Performance

D PHEMT

E PHEMT

GaAs HBT

HFET/MESFETGaN HEMT

GaN MMIC Topology Comparison

Summary of GaN MMIC FB LNA Performance (S-, C-band)

Reference Topology Noise

Figure (dB)

OIP3

(dBm)

P1dB

(dBm)

LFOM

(IP3/Pdc) D (IP3-P1dB)

[1] Matched-FB 2.4 37.8* 9.5:1

[3], [5] Dual-gate FB

1.5 43 30 13

1.03 32 < 25

dBm 2.0:1

[6], [7] Source-Match-

FB

0.75-0.9 44-46 32.9 6.64:1 11-13

0.25-0.45 42-44 32.8 4.2:1 11.2

[12] Darlington 4.3** 43.5 31 3.7 12.5

[11], [13] DA 3.3 29 22 7

4.3** 42-44 30-33 ~2:1 11-12

This Work

[14] Cascode FB

2.5 48.4 36.8 3.5:1 11.7

3 51.9 38.5 5.2:1 13.4

Lowest

NF

Best

Combo

NF-IP3

Best

BW

Poor

thermal

mitigation

Gain

Roll-off

High NF

LF NF

Poor

PAE

GaN Power Doubler Amplifier Typical NTSC CATV Spectrum

CATV upgrades extend the BW beyond 1 GHz adding digital

channels to support HDTV, VOD, & high speed internet

GaN Device CATV Linearity

Courtesy Rainer Hillermeier - RFMD

CATV linearity is related to device Cdg linearity with Vds.

Lower Al composition results in improved GaN CATV linearity.

GaN Device CATV Linearity

[2009 BCTM Conference, Jeff Shealy, et.al.]

GaN provides 3.5 dB higher linear Output Power vs. GaAs

CATV CIN Linearity: GaN vs. GaAs

Courtesy Rainer Hillermeier - RFMD

GaN LNA Future Trends

• Decade BW Performance, No Filter

• Reconfigurable – SDR

• E/D GaN

• Insulated gate (reduce gate shot noise)

• THz Operation

• Linearization

• Heterogeneous Integration w/ Silicon

Acknowledgement

• Northrop Grumman

–Richard To, Wen-Ben Luo, Ioulia Smorchkova, Benjamin

Heying,YaoChung Chen, Mike Wojtowicz, Aaron Oki,

Schaffer Grimm, Willie O. Simmons, Ed Rezek, and Frank

Kropschot

• RFMD

–Rainer Hillermeier, Tony Sellas, Curtis Kitani, Robert Dry,

Don Willis, Daniel Jin, Joe Johnson, Dave Aichele, Jeff

Shealy, Karthik Krishnamurthy, Ramakrishna Vetury, Dane

Henry, Conrad Young, Alastair Upton, Brad Nelson, Dave

Runton, Jay Martin, Norm Hilgendorf

Broadband GaN LNA MMIC

• [1]Grant A. Ellis, et.al., “Wideband AlGaN/GaN HEMT MMIC Low Noise Amplifier,” in IEEE MTT-S Digest, Fortworth, TX, June, 2004, pp. 153-156.

• [2]Hongtao Xu, et.al., “A C-Band High-Dynamic Range GaN HEMT Low-Noise Amplifier,” IEEE Microwave and Wireless Components Letters, vol. 14, no. 6,

pp. 262-264, June, 2004.

• [3]S. Cha, et.al., “Wideband AlGaN/GaN HEMT Low Noise Amplifier for Highly Survivable Receiver Electronics,” in IEEE MTT-S Digest, Fortworth, TX,

June, 2004, pp. 829-832.

• [4]S.E. Shih, et.al., “Broadband GaN Dual-Gate HEMT Low Noise Amplifier,” in IEEE CSIC Symp. Dig., Portland, Oregon, October, 2007.

• [5]Michael V. Aust, et.al., “Wideband Dual-Gate GaN HEMT Low Noise Amplifier for Front-End Receiver Electronics,” in IEEE CSIC Symp. Dig., San

Antonio, TX, Nov., 2006.

• [6]K.W. Kobayashi, et.al., “A 2 Watt, Sub-dB Noise Figure GaN MMIC LNA-PA Amplifier with Multi-octave Bandwidth from 0.2-8 GHz,” in IEEE MTT Digest,

Honolulu, Hawaii, June, 2007, pp. 619-622.

• [7]Kevin W. Kobayashi, et.al., “A Cool, Sub-0.2 dB Noise Figure GaN HEMT Power Amplifier with 2-Watt Output Power,” IEEE Journal of Solid-State

Circuits, October, 2009.

• [8] E.M. Suijker, et.al., “Robust AlGaN/GaN Low Noise Amplifier MMICs for C-, Ku- and Ka-band Space Applications,” IEEE CSIC Symp. Dig. ,Greensboro,

NC, 2009.

• [9] S.E. Shih, et.al., “Design and Analysis of Ultra Wideband GaN Dual-Gate HEMT Low Noise Amplifiers,” IEEE IMS Dig., Boston, MA, June, 2009.

• [10] James Milligan, “Commercial GaN Devices for Switching and Low Noise Applications,” IEEE IMS Workshop Notes, WFA, Anaheim, CA, May, 2010.

• [11] W. Ciccognani, et.al., “An Ultra-Broadband Robust LNA for Defence Applications in AlGaN/GaN Technology,” IEEE IMS Dig., Anaheim, CA, May, 2010.

• [12] Kevin W. Kobayashi, *YaoChung Chen, *Ioulia Smorchkova, *Roger Tsai, *Mike Wojtowicz, and *Aaron Oki, “1-Watt Conventional and Cascoded GaN-

SiC Darlington MMIC Amplifiers to 18 GHz,” IEEE RFIC Symp. ,Honolulu, Hawaii, 2007.

• [13] Kevin W. Kobayashi, *YaoChung Chen, *Ioulia Smorchkova, *Benjamin Heying, *Wen-Ben Luo, *William Sutton,*Mike Wojtowicz, and *Aaron Oki,

“Multi-Decade GaN HEMT Cascode-Distributed Power Amplifier with baseband Performance,” 2009 IEEE RFIC symp., Boston, MA, June 6th.

• [14] Kobayashi, Kevin W. ”An 8-Watt 250-3000 MHz Low Noise GaN MMIC Feedback Amplifier with > +50 dBm OIP3,” 2011 IEEE CSIC Symposium, Hawaii,

Oct. 16-19.

Bibliography

Bibliography

Survivability

• [4-1] M. Rudolph, R. Behtash, R. Doerner, K. Hirche, J. Würfl, W. Heinrich, and G. Tränkle, “Analysis of the Survivability of GaN Low-Noise Amplifiers,”

IEEE Trans. Microw. Theory Tech., vol. 55, no. 1, pp. 37 – 43, Jan. 2007.

• [4-2] P. Parikh, Y. Wu, M. Moore, P. Chavarkar, U. Mishra, R. Neidhard, L. Kehias, T. Jenkins, “High Linearity, Robust, AIGaN-GaN HEMTs for LNA &

Receiver ICs,” Proceedings of the 2002 IEEE Lester Eastman Conference on High Performance Devices.

• [4-3] M. V. Aust, A. K. Sharma, Y.-C. Chen, and M. Wojtowicz, “Wideband Dual-Gate GaN HEMT Low Noise Amplifier for Front-End Receiver

Electronics,” IEEE CSIC Symp. Dig., San Antonio, TX, Nov. 2006.

• [4-4] M. Micovic, A. Kurdoghlian, T. Lee, R. O. Hiramoto, P. Hashimoto, A. Schmitz, I. Milosavljevic, P. J. Willadsen, W.-S. Wong, M. Antcliffe, M.

Wetzel, M. Hu, M. J. Delaney, and D. H. Chow, “Robust Broadband (4 GHz – 16 GHz) GaN MMIC LNA,” 2007 IEEE Compound Semiconductor Integrated

Circuit Symposium.

• [4-5] S. Cha, Y.H. Chung, M. Wojtowicz, I. Smorchkova, B. R. Allen, J.M. Yang, and R. Kagiwada, “Wideband AlGaN/GaN HEMT Low Noise .Amplifier

For Highly Survivable Receiver Electronics,” IEEE MTT-S Digest, Fortworth, TX, June, 2004, pp. 829-832.

• [4-6] M. Micovic, A. Kurdoghlian, H. P. Moyer, P. Hashimoto, A. Schmitz, I. Milosavljevic, P. J. Willadsen, W.-S. Wong, J. Duvall, M. Hu, M. Wetzel , and

D. H. Chow, “GaN MMIC Technology for Microwave and Millimeter-wave Applications,” CSIC 2005 Digest, pp. 173 – 176.

• [4-7] H. Xu, C. Sanabria, A. Chini, S. Keller, U. K. Mishra, and R. A. York, “A C-Band High-Dynamic Range GaN HEMT Low-Noise Amplifier,” IEEE

Microwave and Wireless Components Letters, vol. 14, no. 6, pp. 262-264, June, 2004.

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Material/Device Noise

• [5-1] NGC, unpublished

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with 0.6 dB noise figure at 10 GHz,” IEEE Electron. Lett., vol. 36, no. 3, pp. 469–471, Mar. 2000.

• [5-3] J.-H. Lee, H.-S. Yoon, C.-S. Park, and P. Hyung-Moo, “Ultra low noisecharacteristics of AlGaAs/InGaAs/GaAs pseudomorphic HEMT’s

withwide head T-shaped gate,” IEEE Electron Device Lett., vol. 16, no. 6,pp. 271–273, Jun. 1995.

• [5-4] Y. Ando, A. Cappy, K. Marubashi, K. Onda, H. Miyamoto, and M.Kuzuhara, “Noise parameter modeling for InP-based

pseudomorphicHEMTs,” IEEE Trans. Electron Devices, vol. 44, pp. 1367–1374, Sep.1997.

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vol.17, no. 10, pp. 482–484, Oct. 1996.

• [5-6] M.-Y. Kao, K. H. G. Duh, P. Ho, and P.-C. Chao, “An extremely lownoiseInP-based HEMT with silicon nitride passivation,” in Int.

ElectronDevices Meeting Tech. Dig., Dec. 11–14, 1994, pp. 907–910.

• [6-1] S. Lee, K. J. Webb, V. Tilak, and L. F. Eastman, “Intrinsic Noise Equivalent-Circuit Parameters for AlGaN/GaN HEMTs,” IEEE Trans. Microw.

Theory Tech., vol. 51, no. 5, May 2003.

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Performance,” IEEE Electron Device Lett., vol. 24, no. 9, pp. 535-537, Sep. 2003.

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AlGaN/GaN HEMTs,” IEEE Electron Device Lett., vol. 27, no. 1, Jan. 2006

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of AlGaN/GaN HEMTs,” IEEE Trans. Microw. Theory Tech., vol. 53, no. 2, pp.762 – 768, Feb. 2005.

• Z. H. Liu, G. I. Ng, and S. Arulkumaran, “Analytical Modeling of the Temperature Dependent Microwave Noise in AlGaN/GaN HEMTs,” 2009 IEEE

Int. Symp. On RF Integr. Tech., pp. 276 – 279.

• P. H. Handel and A. G. Tournier, “Nanoscale Engineering for Reducing Phase Noise in Electronic Devices,” Proc. of the IEEE, vol. 93, no. 10, pp.

1784 – 1814, Oct. 2005.

• H. Fukui, “The noise performance of microwave transistors,” IEEE Trans. Electron Devices, vol. 13, pp. 329–341, Mar. 1966.