Jan Verspecht bvba Gertrudeveld 15 1840 Steenhuffel Belgium - - PowerPoint PPT Presentation

Calibration of a Measurement System for High Frequency Nonlinear Devices

Jan Verspecht

Jan Verspecht bvba

Gertrudeveld 15 1840 Steenhuffel Belgium email: contact@janverspecht.com web: http://www.janverspecht.com Slides of the Doctoral Dissertation - Vrije Universiteit Brussel, November 1995

1

Calibration of a Measurement System for High Frequency Nonlinear Devices

Jan Verspecht

2

Overview

• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

3

• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

4

The High-Tech World

5 Idea Prototyping Computing Measuring Producing

Engineering Tools

6

High-Speed Electronic Measurements

Filters Interconnects Small signal amplifiers Dynamic Linear TDR-Oscilloscopes Network Analyzers Mixers Power Amplifiers Frequency Multipliers Static Nonlinear Oscilloscopes Spectrum Analyzers Digital “Nonlinear Network” Dynamic Nonlinear Analyzer

7

a1 b1 a2 b2

DUT Nonlinear input input

• utput
• utput

Vectorial “Nonlinear Network” Analyzer

VNNA Measurements

Amplitude & Phase

8

Instrument Calibration

VNNA Scientific and Industrial World kg s m V A H K J W F Ω Hz

9

• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

10

?

VNNA Hardware

Preexistent Prototypes

Broadband Oscilloscopes Linear Network Analyzer Test Sets Couplers Synthesizers RF Switches Incident & Reflected Amplitude & Phase Port 1 & Port 2

Measurements

“Golden diode” Ideal RF signal samplers RF Power Meter

Phase Cal Amplitude Cal

11

HP-NMDG Prototype

BIAS1 BIAS2 DUT (on wafer)

4 channel broadband downconvertor precision analog-to-digital convertor Bandw.: 18GHz

• Dyn. Range: 60dB

Spec Sheet

12

Traceability Of Calibration

RF Power Meter

Phase Cal Amplitude Cal

Reference Waveform Generator Broadband Sampling Oscilloscope “Nose-to-Nose” Calibration Standards Lab

13

• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

14

Sampling Oscilloscope Basics

DELAY DAC Delay Setting Trigger Level CH1 CH2 CH3 CH4 TRIGGER

∫ ∫ ∫ ∫

Screen

15

Timebase Errors

Drift Jitter Distortion HLog estimator Log Spectral Averaging Noise rms = F(signal derivative) Phase Demodulation

16

Vertical Errors

Gain Distortion Dynamical Limit Signal “Nose-to-Nose” Offset Charact. DC measurements Amplitude

17

• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

18

Impulse Response = Kick-Out

Impulse Response Kick-Out Dirac Delta Precharged +

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“Nose-to-Nose” Measurement

+

• Measured Kick-Out

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Systematic Measurement Error

M ω ( ) H ω ( )e jϕ P ω

( ) ( )

=

measured freq. response function physical freq. response function Fourier transform of sampling aperture waveform MEASUREMENT ERROR

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Upperbound For Phase Error

Sampling Aperture : Finite In Time Positive 10ps

10 20 30 40 50 2 4 6 8 10 12

Frequency (GHz)

• Max. Error ( degrees)

1 Local Max

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Comparison With Power Measurements

10 10 20 20 30 30 40 40 50 50 60 60

• 3
• 3
• 6
• 6
• 9
• 9
• 12
• 12

Frequency (GHz) requency (GHz) Response (dB) Response (dB) Low BW

• w BW

High BW High BW

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Repeatability and Noise

10 20 30 40 50

• 0.2
• 0.1

0.1 0.2 10 20 30 40 50

• 1.5
• 1
• 0.5

0.5 1 1.5

Frequency (GHz) Frequency (GHz) Amplitude Diff. (dB) Phase Diff. (deg)

Amplitude Phase

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Sampler Linearity

frequency (GHz) amplitude differences (dB)

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Frequency Response Function

5 10 15 20 25 30

• 6
• 5
• 4
• 3
• 2
• 1

5 10 15 20 25 30 2.5 5 7.5 10 12.5 15

Frequency (GHz) Frequency (GHz) Amplitude (dB) Phase (deg)

Amplitude Phase

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“Nose-To-Nose” Errors

Amplitude Phase Time Distortion 8mdB 0.02deg Timing Jitter 150mdB / Time Drift / / Repeatab., Noise 20mdB 0.15deg Nonlinearity < 20mdB < 0.15deg Unknown Phase / 0.72deg

(Frequency = 20GHz)

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• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

28

Error Model

Definition of Variables

am1 bm1 am2 bm2 ag1 bg1 ag2 bg2 ad1 bd1 ad2 bd2

LINEAR LINEAR DUT

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Ki e jϕ K i

( )

1 β1

i

γ1

i δ1 i

0 α2

i β2 i

0 γ2

i δ2 i

am1

i

bm1

i

am2

i

bm2

i

ad1

i

bd1

i

ad2

i

bd2

i

=

classical calibration (LOS, LRM) powermeter reference generator

Calibration

30 reference gen.

Absolute Calibration

power sensor

Amplitude Phase

PORT 1 PORT 1

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probe tip APC-3.5 RECIPROCITY

On Wafer: Reciprocity

power sensor reference gen.

Data Acquisition Line

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The Reference Generator

1GHz trigger signal amplifier (0.5W) 1.5m SMA cable SRD module differentiator 20dB att. APC-3.5 conn. (m)

200 400 600 800 1000

• 240
• 180
• 120
• 60

60 120 180 240

Time (ps) Amplitude (mV)

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Absolute Calibration Factor

3 6 9 12 15 18

• 45
• 40
• 35
• 30
• 25
• 20

3 6 9 12 15 18 16 17 18 19 20 21

Frequency (GHz) Frequency (GHz) Amplitude (dB) Phase (deg)

Amplitude Phase

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• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

35

Model vs. Measurements

DUT

Large Signal Model

Simulation

s-parameters as a function of DC bias (Root or Jansen et al.)

VNNA Data

=

?

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Early Results

: Root-model : VNNA measurements

MESFET transistor (INTEC-UG, IMEC): HDA, fundamental 3GHz

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More Advanced Results

• 25
• 20
• 15
• 10
• 5
• 60
• 50
• 40
• 30
• 20
• 10

Harmonic output power (dBm) Input power (dBm) : Jansen et al. model : VNNA measurements

• 25
• 20
• 15
• 10
• 165
• 160
• 155
• 150
• 145

Input power (dBm) Phase (deg)

HEMT transistor (ESAT-KUL, IMEC): HDA, fundamental 3GHz

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Time Domain

100 200 300 400 500 600

• 0.15
• 0.1
• 0.05

0.05 0.1

Time (ps) Amplitude (V)

: VNNA measurement : Jansen et al. model : incident voltage wave

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• Introduction
• Vectorial “Nonlinear Network” Analyzer Hardware
• Accuracy of Broadband Sampling Oscilloscopes
• The “Nose-to-Nose” Calibration Procedure
• Absolute Calibration of a VNNA
• Consistency Check: Model versus Measurements
• Conclusions

40

Conclusions

• The Instrumentation And Calibration

Procedure Developed Allows the Accurate Measurement of Phase and Amplitude of the Spectral Components of Incident and Scattered Voltage Waves at the Signal Ports

• f a Nonlinear Microwave Device.
• The Relative Calibration And Amplitude

Calibration Are Traceable To National Standards, The Phase Calibration Is Traceable To The “Nose-To-Nose” Calibration Procedure.

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Future Research

• Phase Calibration Traceable To National Standards
• More Theoretical Work Concerning “Nose-To-Nose”
• Implementing The “Nose-To-Nose” For

Photo-Conductive Samplers

• Putting Error Flags On VNNA Measurements
• Towards Commercial Use Of VNNA