Non-coaxial Measurements

The capability of making non-coaxial measurements is available with the HP 8753 family of analyzers with TRL* (thru-reflect-line) or LRM* (line-reflect-match) calibration. For in-depth information on TRL*/LRM* calibration, refer to Chapter 6, “Application and Operation Concepts. n

Non-coaxial, on-wafer measurements present a unique set of challenges for error correction in the analyzer:

w The close spacing between the microwave probes makes it difficult to maintain a high degree of isolation between the input and the output.

nThe type of device measured on-wafer is often not always a simple two-port.

w It may be difficult 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, short, open, load, thru (SOLI’) calibrations can also be done and may be preferred due to the better accuracy of the SOI. calibration method.

For information on how to perform TRL* or LRM* calibrations, refer to the section “TRL+ and TRIW Error-Correction” in Chapter 5, “Optimizing Measurement Results”

Making Measurements 2-81

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HP 8753E manual Non-coaxial Measurements