Noise Parameter Basics - tactron.de · ReceiverLNA 50 O F.rec Noise Noise€Source Receiver ......

Dr. Zacharia OuardirhiDipl. Ing. Matthias Beer MBA

NoiseParameter

Basics

Presentation Outline

•Noise Figure vs Noise Parameter•Noise Parameter Extraction•Noise Parameter Measurement Setups•Noise Parameter Verification

Copyright Focus Microwaves Inc. 2014 2

Noise Figure Definition


Output Signal = Input Signal * Gain: S.out = S.in * GOutput Noise = Input Noise * Gain + Internal Noise: N.out = N.in * G + N.dut

Noise Figure is the“Signal/Noise Ratio

Degradation”through the media (DUT)

in

in

NS

+

Na

Ga

out

out

NS

Ga

Ga+Na

Output

Input

SNRSNR

NF

Noise Figure vs Noise Parameters

4

To design a Low Noise Amplifier you need the four NoiseParameters, not only the Noise Figure

This transistor has a

noise figure of

2.9dB at 50

but a minimum noise

figure of

0.85dB at 100+j150

Copyright Focus Microwaves Inc. 2014

Noise Circles

Gain Circles

Stability Circles

Noise Parameter Measurement SetupThe tuners synthesize.source

F.dut = F.total – (F.rec1)/Gav.dut

• A twoport device has 4 Noise Parameters• To determine them at least 4 x .source are needed• Focus method uses many more (~50)

.source

Input Tuner

ReceiverLNA

50

F.rec

NoiseReceiverNoise Source

F.total

5Copyright Focus Microwaves Inc. 2014

Extract DUT Noise Figure

• Using FRIIS’formula for a cascade of amplifiers with NoiseFigure Fi and Available Gain Gi

F.total = F1 + (F21)/G1 + (F31)/(G1*G2) …• We derive

F.dut( s)=F.total( s) – {F.rec( dut( s))1}/G.dut( s)where:dut( s) = S22 + (S12*S21* s)/(1S11* s)

6

DUT{Sij}

s

dut = f( s)

ReceiverF.rec


• Noise Figure depends on Ys as follows:F (Ys) = Fmin + Rn/Gs * |Ys – Yopt|2

• This is the equation of a parabolichyperboloid surfacewith a set of isometric circles on the Ys Smith Chart,with F as parameter

Four Noise Parameters


Determination of 4 NP


Wideband Stability

9

Stability Circle(: s for dut=1)

Tuning Range

Min Freq

Max Freq

ATTENTIONThe DUT may oscillate at lowfrequencies, even though wemeasure at high frequencies,because the tuner is wideband!

opt > Fmin

s


Wideband Impedance Spread

10

Stability Circle(: s for dut=1)

Tuning Range

Min Freq

Max Freq

For fast noise measurements, thetuner has to move least, this meansthe impedance points cannot beoptimum at all frequencies

NFmin

s


Source Impedance Patterns• Low Density Pattern 1

(1221 points) = spiral starting atS11* at fmin and fmax and fmedif fmax/fmin> 4

• High Density Pattern 2(2550 points) Same as above

• Target Pattern 3(2550 points) = triangle centeredaround S11*, else as above

• Customized tuning pattern11

S11*

S11*


Selecting Valid Noise DataMonitor various (user defined) criteria to maintain thequality of the measured data.

•Maximum sFilters out any measured point with s > Limit

•Mismatch limitMismatch Factor shows the distance of s from the input stabilitycircle of the DUT. The larger the number, the closer s to the stabilitycircle.

•Oscillation AvoidanceMonitors the fluctuations in DC current to detect instabilities. Skip thecurrent measurement source impedance at all frequencies.


Noise Data Processing use SVD


• Singular Value Decomposition (SVD)• In linear algebra, the singular value

decomposition (SVD) is an importantfactorization of a rectangular real orcomplex matrix, with manyapplications in signal processing andstatistics. Applications which employthe SVD include computing the pseudoinverse, least square fitting of data,matrix approximations, and determinethe rank, range and null space of amatrix

• Use at least 8 measured impedancepoints

Effect of Filtering on Noise Data

15

Raw Data

Filter

Filter&Smooth


16

ONMONMDUTINMINMENR

Focus Focus

INM: Input Noise ModuleONM: Output Noise Module


VNAVNA NFANFA

SourceTuner

Noise Measurement Setup 1

VNA is measuringSParameters of DUTand NFAnalyzer the NF

VNAVNA

Noise Measurement Setup 2


ONMONMDUTINMINM

SourceTuner

Focus


Focus

VNA is measuringSParametersand NF of DUT


Noise ParameterMeasurement SetUp with ZVA only*

ONMONMDUTINMINM

LANControl

Focus

Focus

Focus


Tuner

* above 24GHzadditionalaccessories for ZVAoption K30 are required

18

Noise ParameterMeasurement SetUp with PNAX (Opt.029)

Test port 1

R1

Test port 2

R2A B

Source 2Output 1

Source 2Output 2

rear panel+28V

Noise receivers

10 MHz 3GHz

3 26.5GHz

Source 1OUT 1 OUT 2

Pulsemodulator

Source 2(optional)

OUT 1 OUT 2

Pulsemodulator

Noise receivers

J9J10J11 J8 J7 J2 J1

+

Tuner

To receivers

LO


DUT

Noise Measurement Setup (PNAX)The PNAX has two noisereceiver options:1.Option 029: TrueNoise Receiver (based onNoise Source and 8975)2.Option 028: RMS/AVG(signal only)

Focus supports bothmethods


Wideband tuner 0.726GHz tomatch the PNAX 26


Broadband Noise ParameterSystem Components

Input Module

Output Module

Control ModuleLAN/TCPIP

21

Load Pull and Noise System

22

Low Frequency Noise Parameter System – 0.310GHz


Load Pull and Noise System

23

High Frequency Noise Parameter System 1067GHz



Ultra Wideband Noise Parameters0.367GHz

Noise Parameter Verification


The problem…

• A load pull test setup can be verified using the backtoback

(B2B) method: one tuner conjugate matches the other one at

many points using a THRU as a DUT.

• If the Gain is 1 then the system is accurate.

*


Load Pull Setup Verification


Gt=0.03dB

In Noise things are not so easy…• Noise Parameters are not measured, they are calculated

Noise model: F = Fmin + Rn/Gs*|YsYopt|2

• 4 accurate noise measurements would beenough to determine Fmin, Rn, Yopt=Gopt+jBopt

This is never the case, measurements in generaland noise measurements in particular are “noisy”

Therefore we use > 4 points and process the data

• Assuming the hardware is correct, the whole noisemeasurement literature over the last 50 years has been about

Choosing the “right” Ys points

Properly “processing” the data28Copyright Focus Microwaves Inc. 2014

What is a“Noise Standard”

• A “Standard” is a device of which weknow, ahead of time, the exact physicalproperties like the 4 noise parameters

• A practical noise standard is one users canproduce themselves.

• Passive networks, without noise sourcesother than thermal, are such standards.

• Data sheets measured by “other systems”are not noise standards, they are simplereferences for comparison.


Why are passive networksNoise Standards ?

It comes from the definition of Noise Figure:

• Noise Figure F = SNRIN / SNROUT

• F (Ys) = Available Loss = 1/Gav(Sij,Ys)• Calculate F for an arbitrary set of {Ysi} 4NP

{Sij}

Signal

Thermal Noise

Thermal Noise

Signal/LossYs


Accuracy of Noise Parameter

F(Ys, Sij) =1/Gav =(|1 s*S11|2*(1| o|2 )/(|S21|2 *(1| s|2))where o = S22 + S12*S21/(1 s*S11)

s = (1Ys/Yo)/(1+Ys/Yo); Yo=20mS.


Test Equipment used:


Receiver 1: Miteq LNA1 (up to 18GHz) + PNAX

Receiver 2: Miteq LNA2 (up to 26GHz) + PNAX

Receiver 3: Miteq LNA2 + R&S Spectrum analyzer.

Noise Data Processing

Raw Data(3 samples)

StatisticalProcessing,Fmin

StatisticalProcessing,Rn

Theory


Matched Attenuator 3dB

Enable PostExtractionOptimization


Attenuator – 6dB


Attenuator – 9dB


The raw data (measurement) have been correctThe true result is contained in the raw dataStatistical processing used to extract the final data has been correctThere cannot be a “coincidental agreement”

over such a wide frequency range.

Why is that important ?


Mismatched passive Standard


Sparameter of mismatched Standard


Limited accuracy

High passFilter

NPar of mismatched Standard

Theory


Noise Parameters to verify F50


NPar Verification thru F50

F50 = Fmin + Rn/Gso * |YsoYopt|2

… Yso=Gso+jBso: Tuner Initialized

• Measuring Fdut at 50 = F50 (Tunerinitialized)• Calculating F50 from extracted 4 NPar


Verification thru F50

43

F50 = Fmin + Rn/Re(Yso) * |YsoYopt|2 with Yso @ TunerInitialized

• Measuring FDut at 50 = F50 ( tuner init)• Calculating F50 from extracted NPar


Yso(f)

F50.cF50.m

F50.cF50.m

0.45dB

+0.45dB

ConclusionsFocus offers Wideband noise parameter solution• The widest band tuners• Support of VNA, Spectrum Analyzers and NFM

Passive noise standard testing allows• Verifying the raw data• Verifying the Extraction• Verifying the Statistical Math (Averaging)

F50 testing allows• Consolidating active device data


Focus Microwaves Winning through Innovation

Noise Parameter Basics - tactron.de · ReceiverLNA 50 O F.rec Noise Noise€Source Receiver ......

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Transcript of Noise Parameter Basics - tactron.de · ReceiverLNA 50 O F.rec Noise Noise€Source Receiver ......