Technical data

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Operating Concepts
Calibration Routines
Calibration Routines
There are twelve different error terms for a two-port measurement that can be corrected by accuracy
enhancement in the analyzer. These are directivity, source match, load match, isolation, reflection tracking,
and transmission tracking, each in both the forward and reverse direction. The analyzer has several
different measurement calibration routines to characterize one or more of the systematic error terms and
remove their effects from the measured data.
The calibrate menu allows you to perform the measurement calibration routines. These procedures range
from a simple frequency response calibration to a full two-port calibration that effectively removes all
twelve error terms.
Response Calibration for All Device Types
The response calibration provides a normalization of the test setup for reflection or transmission
measurements. This calibration procedure may be adequate for measurement of well matched devices.
This is the simplest error-correction to perform, and should be used when extreme measurement accuracy
is not required. You can access this calibration by pressing the RESPONSE softkey within the calibrate
menu
Response and Isolation Calibration for All Device Types
The response and isolation calibration provides a normalization for frequency response and crosstalk
errors in transmission measurements, or frequency response and directivity errors in reflection
measurements. This procedure may be adequate for measurement of well matched high-loss devices. You
can access this calibration by pressing the RESPONSE & ISOL'N softkey within the calibrate menu.
Response and Match for O/E and E/O Devices
The response and match calibration removes the frequency response errors and electrical port match
errors. The port match errors occur because of reflections between: 1) The electrical output port of the
analyzer and the input port of an E/O device, and 2) The output port of an O/E device and the electrical
input port of the analyzer. You can access this calibration by pressing the
RESPONSE & MATCH softkey
within the calibrate menu.
Optical Calibration Kit Modifications
Characteristics of the optical calibration standard models in the analyzer can be modified to more closely
match the actual standards in use.
Definitions
• Fresnel Reflection: The reflection of a portion of incident light at a planar interface between two
homogenous media having different refractive indexes.
For calibration standards, this term is used to refer to an optical fiber-air interface. The
most common type of Fresnel reflection used for calibration is that formed by an
unterminated connector. Theoretically, the amount of power reflected at this interface is
3.5%. That is, 3.5% of the optical power is reflected back to the source and 96.5% is
transmitted from the cable into air.
• Reflector: A device that causes the abrupt reversal of direction of a light beam. Reflection from a
smooth surface is termed specular, while reflection from a rough surface is termed diffuse.