Specifications

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安捷倫科技高頻元件量測研討會
Feb.23, 2006
Offset Load Calibration Overview
Offset load calibration originated with 8510
Offset load is a compound standard – load is connected multiple
times with differing offsets
In simplest and most common form, there are just two connections:
the load by itself, and the load with an offset
Similar to a sliding load standard, except
offsets are set by a known, precise
transmission line (e.g., a waveguide section)
Not the same as a load standard
with defined delay, which is a
single standard
Offset (shim)
Load
1. Measure load by itself 2. Measure load plus offset
offset
Page 66
安捷倫科技高頻元件量測研討會
Feb.23, 2006
Offset Load Calibration Advantages
Provides higher directivity and load match accuracy when the definition of the
offset is better known than the load definition
Does not require a dual reflectometer VNA as it uses SOLT error model
instead of TRL error model
Ideal for 1-port calibrations
Also helpful in situations where calibration planes cannot physically move,
such as fixed probe or waveguide positions, where TRL calibrations are
difficult
Offset standard can include
loss term (especially valuable
near cutoff
frequency)
Probe Probe
Probe Probe
Not a good
TRL standard
Attenuation constant
in WR-159 waveguide