Agilent Technologies E5070B, Руководство пользователя

Страница: 130 / 769

124 Chapter 4
Calibration
Full 4-Port Calibration
Full 4-Port Calibration
In full 4-port calibration, calibration data are measured by connecting an OPEN standard, a
SHORT standard, or a LOAD standard to the four test ports (or a THRU standard between
the four ports). This calibration effectively eliminates the directivity error, crosstalk, source
match error, load match error, frequency response reflection tracking error, and frequency
response transmission tracking error from the test setup in a transmission or reflection test
using those ports (Figure 4-19). As in full 2-port calibration, this calibration method also
makes it possible to perform measurements with the highest possible accuracy. There are
unique error terms for directivity, source match, and reflection tracking for each stimulus
test port (3
×
4 ports = 12). As for isolation, load match, and transmission tracking errors,
there are unique terms for each combination between a stimulus port and a response port (3
×
12 combinations = 36). Therefore, in total, 48 error terms are involved in a full 4-port
calibration.
Figure 4-19 Full 4-port error model (Options 413 and 414)