2023-02-21 13:33 Status: # Calibration ## DC Probes Point probes to the sky, number 1 is on the left. Pressure and location has to be consistent for each test standard. At least 2 months to repair DC probes. Steve damaged on once on a critical project, not nice! 100 micron length to stabilise the signal. ## Types of Tests ### TRL Through, reflection, line. #### Through Wherever the reference plane is, that gets met to the reference plane of the other probe.  #### Reflection  Need a near perfect open at the reflection plane. #### Line Disadvantage - can be too long at low frequencies to obtain the required phase shift range. 20-160 degrees for S21 phase is the range that the calibration works for.