JGBdVwide band low noise receiver

Technology Perspective and Technology Perspective and results with mHEMTsresults with mHEMTs

Jan Geralt Bij de Vaate

ASTRON

JGBdVwide band low noise receiver SKADS Workshop 2007

SpecificationSpecificationR Schillizi et. al. Sept. ‘07R Schillizi et. al. Sept. ‘07

• Tinstrument= 40K (excluding sky noise), goal 30K

• BW 70MHz – 1.0 GHz (two systems)

• Survey speed ~1/T2

• Sensitivity ~1/T

JGBdVwide band low noise receiver SKADS Workshop 2007

CostingCosting

• A 9 million element system with a total system cost of 250M € can spend:– 1,5 € per LNA per Kelvin improvement (Survey)

– Or 8,5 € for 5 Kelvin improvement, again for Surveys

• Given a bare die costs of:– 0,5 € for Silicon technologies (only 500 12 inch wafers)

– 2 € for GaAs technologies (2000 6 inch wafers)

• Low cost technologies cannot compromise on noise!

JGBdVwide band low noise receiver SKADS Workshop 2007

TechnologyTechnology

• GaAs PsHEMT / mHEMT

• SiGe BJT

• with b0 =100: FMIN~30K

• CMOS

• In principle similar to GaAs

sgmT

MIN rrgf

fF 1

20

22

20

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fn

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frr

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I

f

fnF TT

BET

C

TMIN

211 cf

fF

TMIN

Amplifier Noise Figure Trends @1.4 GHz Tamb=290K

0

10

20

30

40

50

60

70

2000 2002 2004 2006 2008 2010 2012

year

No

ise

Tem

per

atu

re

III/V: GaAs or InP

SiGe

CMOS

JGBdVwide band low noise receiver SKADS Workshop 2007

PsHEMTPsHEMT

• 0.2um technology

• OMMIC differential LNA– 2109

– ASTRON design

JGBdVwide band low noise receiver SKADS Workshop 2007

InPInP

• Differential LNA

• NGST

JGBdVwide band low noise receiver SKADS Workshop 2007

mHEMTmHEMT

• 70nm OMMIC technology – 250GHz fT

– Differential design

– Optional on-chip biasing

JGBdVwide band low noise receiver SKADS Workshop 2007

mHEMTmHEMT

• 70nm OMMIC technology – 250GHz fT

– Differential design

– Optional on-chip biasing

JGBdVwide band low noise receiver SKADS Workshop 2007

mHEMTmHEMTATNF01_40LNA_05A, Russel GoughATNF01_40LNA_05A, Russel Gough

• 70nm OMMIC technology

• Designed for 30-50 GHz band

• 4-stage low-noise amplifier

• Transistors: 6-fingers, 90um gate width

• Bias: – Vds = 1.0 V

– Id = 13 mA

JGBdVwide band low noise receiver SKADS Workshop 2007

ATNF01_40LNA_05AATNF01_40LNA_05A

• 10 circuits were delivered – sample of 4 was measured

• 1 circuit was unstable (|S11|>1)

• The performance of remaining 3 circuits was similar

• Measured gain is greater than modelled

• Input and output match is poorer than expected

JGBdVwide band low noise receiver SKADS Workshop 2007

SiGeSiGe

• IBM technology– 8HP (0.13µm) : sub 0.5dB noise figure possible

• 0.25dB for 9HP??

– (relative) high Rn

– Good power match possible

– Limited cooling boosts current gain β:

Weinreb 2005

JGBdVwide band low noise receiver SKADS Workshop 2007

JGBdVwide band low noise receiver SKADS Workshop 2007

• SKA / LOFAR workshop!(or focussed session)

vaate@astron

JGBdVwide band low noise receiver SKADS Workshop 2007

ConclusionConclusion

• SKA specifications for AA within reach it seems but…– T coupling (<5) (active reflection coefficient)

– T spill-over, ground noise (<5)

– T antenna losses (<5)

• Technology choice will be based on performance

• Good case for III/V, but also CMOS