Multiport Calibration

ATE Architecture, Design and Support

What We Do

Solve challenging high-speed and microwave measurement problems, providing customers with accurate, reliable, and repeatable data

FixturingCalibration & Error CorrectionReference Plane Positioning

Areas of Expertise

Test System HW & SW Develop-ment

Measurement Science

Fixturing

Calibration & Error Correction Data

Analysis

ATE System Development

•RF•High-Speed•Multi-port

•SMT•Non-coaxial•Device-specific

•Conventional•Novel •Signal Integrity

•Power Integrity

Simple

Company Philosophy

Fast

Simultaneously make measurement systems:

Accurate

Description of Problem

• Multi-port Device Under Test• Switch Matrix & Test Cables have non-

negligible loss, group delay, dispersion• Must calibrate at DUT port• Calibration must be done at least once

per day• Manual calibration is time-consuming

and error-prone• Time required to calibrate reduces

system throughput

Why It Matters

• Poor (or no) calibration results in poor measurement accuracy• Poor accuracy causes

- Bad parts to pass through, or- Good parts to be scrapped

• Both represent real costs through- Higher-level system failures & customer relations issues, or- Increased material costs due to scrapage

• Time required for calibration takes away from system throughput and must be minimized to reduce cost per tested part

Conventional ApproachesDescription Advantages Disadvantages

SOLT cal at VNA only

Simple, fast Poor accuracy

SOLT cal at DUT ports

Potential for very good accuracy

Very time consuming for large devices

Manual process is error-prone

SOLT cal at VNA, characterize and de-embed to DUT

Potential for good accuracy

Tedious to characterize each path

Cal not updated for changes due to environment or mechanical flexure

ATE Solution

1 Calibrate at VNA test ports

2 Automatically characterize interconnect path in situ

Calibration can be done with DUT connected

3 Measure DUT

Measurement done with cal modules connected

4 Automatically de-embed interconnect and display data at DUT reference plane

Instrument Calibration

Module

FCM

FCM

FCM

FCM

FCM

FCM

FCM

FCM

Reference PlanesFCM = Fixture Characterization Module

VNA & ICM

Fixture Characterization Module

Calibration Procedure

4-Ports2000 pointsIFBW = 3000HzCalibration time = 48 sec

Measurement Procedure

4-Ports2000 pointsIFBW = 3000HzMeasurement time = 9 sec

2-Port Probe System Configuration

2-port Calibration Process: Bring Port 1 probe down on Short Measure Short on Port 1 Bring Port 1 probe down on Open Measure Open on Port 1 Bring Port 1 probe down on Load Measure Load on Port 1 Bring Port 2 probe down on Short Measure Short on Port 2 Bring Port 2 probe down on Open Measure Open on Port 2 Bring Port 2 probe down on Load Measure Load on Port 2 Bring Port 1 and Port 2 probes down on Thru Measure Thru between Ports 1 & 2

2-port Calibration Process: Press Calibrate Button

Option 1Traditional ApproachATE Approach

2-Port Probe System ConfigurationOption 2

Calibration Process: Bring Port 1 and Port 2 probes down on Thru Measure Thru between Ports 1 & 2

Compared to Option 1: Hardware configuration simplified Does not allow calibration on-the-fly

ATE Approach

4-Port Probe System Configuration

Switch Matrix

4-port Calibration Process: Approximately 30 steps4-port Calibration Process: Press Calibrate Button

Traditional ApproachATE Approach

Software: Programmatic Module Control

• SCPI-based command set• TCP/IP over Ethernet• VISA compatible• Web Browser Interface to configure Module Controller• Full VISA-based LabVIEW and CVI Wrappers provided

Example Command (Set FCM at module port 5 to thru state):CONTROL:FCM5:STATE THRU

Software: Automated Cal with TruCal

• Application Programming Interface (API) for all ATE Calibration Algorithms

• Standard Win32 DLL• Callable from any language/IDE that supports DLL

access (e.g. C, C++, LabVIEW, CVI, VB, etc.)• Uses rudimentary C data types for maximum

compatibility• Full LabVIEW API Wrapper provided

Example Function (Initialize 2-port algorithm):TC2P_Initialize(double* dFreqs, int nFreqs, int nStates);

Characteristics: Automated

• In situ calibration allows system to be calibrated without removing DUT and connecting standards

• No manual, error-prone operations• Fast calibration improves system availability• Non-intrusive calibration allows it to be done more

frequently

Characteristics: Accurate

• Calibration transfer standards have TRL-level accuracy• In situ calibration removes inaccuracies resulting from

test cable performance with flexure of conventional cal methodologies

• Fast calibration facilitates more frequent calibration as needed

Characteristics: Cost-Effective

• Improved accuracy avoids costs associated with shipping bad material resulting in high-level system failure and customer dissatisfaction

• Improved accuracy avoids scrapping good material just when it has the maximum value-added, reducing manufacturing cost

• Increased system up-time reduces cost per tested part by being able to test more devices in a shift

Contact information

For more information please contact us at:

ATE Systems, Inc. Phone: +1-978-362-185085 Rangeway Road email: info@atesystems.comNorth Billerica, MA 01862 http://www.atesystems.com