Network Analyzers From Small Signal To Large Signal Measurements

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Network AnalyzersFrom Small SignalTo Large
Signal Measurements

• Doug Rytting

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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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Network Analyzer Block Diagram
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Improvements with Correction
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Improvements with Correction
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Calibration Examples 8 Term Model
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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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Power Sweep - Compression
Saturated output power
Output Power (dBm)
Compression region
Linear region (slope small-signal gain)
Input Power (dBm)
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Power Sweep -Gain Compression

• 1 dB compression input power resulting in 1 dB
  drop in gain
• Ratioed measurement
• Output power available (non-ratioed measurement)

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Power Sweep - AM to PM Conversion
Ch1Mkr1 -4.50 dBm 20.48 dB
Ch2Mkr2 1.00 dB 0.86 deg

• Use transmission setup with a power sweep
• Display phase of S21
• AM - PM 0.86 deg/dB

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Start -10.00 dBm
Stop 0.00 dBm
CW 900.000 MHz
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Start -10.00 dBm
Stop 0.00 dBm
CW 900.000 MHz
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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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Hot S22 Measurement System
Small signal S-parameters of a nonlinear device
in the presence of a high power drive signal Df
away from test frequency.
High Power Combine
DUT A
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Hot S22 Measurement System
S-parameters of a nonlinear device at a defined
input or output power.
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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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Load Pull Measurement
Need to measure nonlinear device behavior under
actual operating conditions
Parameter changes vesus output power level
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Load Pull System
INPUT IMPEDANCE AND POWER MEASUREMENT SYSTEM
OUTPUT IMPEDANCE AND POWER MEASUREMENT SYSTEM
X
X
X
X
DUT
INPUT TUNER
OUTPUT TUNER
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Types of Output Tuners
Harmonic load-pull
Passive load-pull
Active load-pull
Simultaneous Drive
OSC
DUT
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Harmonic Load Pull System
Four Channel Frequency Converter HP 8510C/85110A
LO Synthesizer Can be Tuned to Harmonics
Port 3 Coaxial and power cals.
DUT
Reflectometer Mounted on Prober
Input Amplifier 1 - 50 GHz TWA
Port 1 Input Probe
Port 2 Output Probe
Port Drive PIN Switch
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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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High Power Device Pulse Measurements

• Control DUT Temperature
• Eliminate temperature as a variable
• Test high power devices on-wafer at full power
• Measure devices in "unsafe" DC operating area
• Test "pulsed" devices in a pulsed environment
• Test environment final application (GSM)
• Pulsed radars/phased array antennas/high power
  MMIC's
• Improve device characterization data
• Model power FET's at full power level
• Measure IV curves without temperature effects
• Investigate trapping effects in GaAs

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Pulse System Capabilities

• Synchronization of pulses
• IV plane characterization
• Point in pulse vs Frequency or Pulse profile vs
  Time

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Pulsed Bias/RF Meas System

RF Synthesizer
Measurement Controller
LO Synthesizer
Network Analyzer
Bias Network

Drain / Collector Bias Pulser
Gate / Base Bias Pulser

DC Power Supply
Digital Multimeter
Trigger
Pulse Generator
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Agenda

• Small Signal Measurements Error Correction
• Compression and AM to PM
• Hot S22 Measurements
• Load Pull Measurements
• Pulse Measurements
• Large Signal Network Analyzer Measurements

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Large Signal Network Analyzer
Complete Spectrum Waveforms Harmonics and
Modulation
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Large Signal Network Analyzer

• Measures magnitude and phase of incident and
  reflected waves at fundamental, harmonic, and
  modulation frequencies.
• Calibrated for relative and absolute measurements
  for both linear and nonlinear components at the
  device under test.
• Calculate calibrated voltage and current in both
  the time and frequency domains.
• Combination of a vector network analyzer,
  sampling scope, spectrum analyzer and power
  meter.

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LSNA System Block Diagram
Sampler Front End Requires high BW IF Requires
Harmonic LO
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Sampling Converter Fundamentals
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LSNA System Block Diagram
Mixer Front End Requires harmonic sync Can use
high BW IF for modulation Or low BW IF if no
modulation
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Nonlinear Calibration - Model
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Nonlinear Calibration

• Relative calibration at the fundamental and
  harmonic frequencies determines the 7 normal
  error terms.
• Power calibration at the fundamental and harmonic
  frequencies determines the magnitude of K.
• Phase reference generator calibration determines
  the phase of K relative to the fundamental
  frequency.
• Reference generator is an impulse that must be
  accurately modeled or measured.

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Example 1

• Complete device measurement capability using a
  Large Signal Network Analyzer (LSNA).

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Device Measurement
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Example 2

• Device measurement verification and
  measurement-based model improvement.

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Model Verification Improvement
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Model Verification Improvement
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Model Verification Improvement
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Vector Network Analyzer References
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Large Signal Network Analyzer References