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Non-coaxial Measurements
The capability of making non-coaxial measurements is available with the HP 8753 family of
analyzers with TRL* (thru-reect-line) or LRM* (line-reect-match) calibration. F or indepth
information on TRL*/LRM* calibration, refer to Chapter 6, \Application and Operation
Concepts ."
Non-coaxial, on-wafer measurements present a unique set of challenges for error correction in
the analyzer:
The close spacing between the microwave probes makes it dicult to maintain a high degree
of isolation between the input and the output.
The type of device measured on-wafer is often not always a simple two-port.
It may be dicult to make repeatable on-wafer contacts due to the size of the device contact
pads .
Due to the simplicity of the calibration standards , TRL* or LRM* calibrations may be used
for non-coaxial applications such as on-wafer measurements . This type of calibration with
time domain gating and a variety of probe styles can provide optimal accuracy in on-wafer
measurements . At frequencies where on-wafer calibration standards are available , SOL T
calibrations can also be done and may be preferred due to the better accuracy of the SOL T
calibration method.
F or information on how to perform TRL* or LRM* calibrations , refer to the section \TRL* and
TRM* Error-Correction" in Chapter 5, \Optimizing Measurement Results ."
2-76 Making Measurements