Agilent Technologies 8510-58 manual Table of contents

Known devices called calibration standards provide the measurement reference for net- work analyzer error-correction. This note covers methods for specifying these stan- dards and describes the procedures for their use with the Agilent Technologies 8510 net- work analyzer.

The 8510 network analyzer system has the capability to make real-time error-corrected measurements of components and devices in a variety of transmission media. Fundamentally, all that is required is a set of known devices (standards) that can be defined physically or electrically and used to provide a reference for the physical inter- face of the test devices.

Agilent Technologies supplies full calibration kits in 1.0-mm, 1.85-mm, 2.4-mm, 3.5-mm, 7-mm, and Type-N coaxial interfaces. The 8510 system can be calibrated in other inter- faces such as other coaxial types, waveguide and microstrip, given good quality stan- dards that can be defined.

The 8510’s built-in flexibility for calibration kit definition allows the user to derive a precise set of definitions for a particular set of calibration standards from precise physi- cal measurements. For example, the charac- teristic impedance of a matched impedance airline can be defined from its actual physi- cal dimensions (diameter of outer and inner conductors) and electrical characteristics (skin depth). Although the airline is designed to provide perfect signal transmis- sion at the connection interface, the dimen- sions of individual airlines will vary somewhat—resulting in some reflection due to the change in impedance between the test port and the airline. By defining the actual impedance of the airline, the resultant reflection is characterized and can be removed through measurement calibration.

The scope of this product note includes a general description of the capabilities of the 8510 to accept new cal kit descriptions via the MODIFY CAL KIT function found in the 8510 CAL menu. It does not, however, describe how to design a set of physical standards. The selection and fabrication of appropriate calibration standards is as var- ied as the transmission media of the partic- ular application and is beyond the scope of this note.

Table of contents

3	Introduction
3	Measurement errors

3Measurement calibration

4Calibration kit

5Standard definition

5 Class assignment

7Modification procedure

7Select standards

8Define standards

9Standard number

9	Standard type
9	Open circuit capacitance: C0, C1, C2 and C3

11Short circuit inductance: L0, L1, L2 and L3

12Fixed or sliding

12	Terminal impedance
12	Offset delay
14	Offset Z0

14Offset loss

15Lower/minimum frequency

16Upper/maximum frequency

16Coax or waveguide

17Standard labels

17Assign classes

17Standard classes

18S11A,B,C and S22 A,B,C

18	Forward transmission match/thru
18	Reverse transmission match/thru

18Isolation

19Frequency response

19	TRL Thru
19	TRL Reflect
19	TRL Line

19Adapter

20Standard class labels

20 TRL options

20Calibration kit label

21Enter standards/classes

21Verify performance

22User modified cal kits and Agilent 8510 specifications

22Modification examples

22Modeling a thru adapter

23Modeling an arbitrary impedance

23 Appendix A

Calibration kit entry procedure

26Appendix B

Dimensional considerations in coaxial connectors

29Appendix C

Cal coefficients model

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