China Electronics Technology Instruments AV3672 Series, Руководство пользователя

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7 Calibration
7.9 Fixture Compensation Calibration
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the key to fixture embedding and de-embedding. However, it is difficult to determine the S-parameter. One of the
current feasible methods is to establish the fixture model by linear simulation or simulate the fixture with the three-
dimensional electromagnetic structure, and the other method is used to determine the fixture loss and delay time by
means of port extension.
➢
Touchstone data file (SnP file)
It is a data format created by EEsoft before purchase by HP, or widely known as the S2P format. If multiple ports
are extended, the file is generally known as the SnP file, where n represents the number of ports. The corresponding
S-parameters of n ports are saved in this file.
➢
Circuit parameter model
The impedance of the components and circuits should be matched in the microwave component and circuit design
phase. Generally, the conjugate matching circuit is composed of the resistance (R), inductance (L), capacitance (C)
and conductance (G) in the impedance matching design. The parameter form of the conjugate matching circuit is
referred to as the circuit parameter model.
7.9.2 Fixturing On/Off
Menu path: [Cal] > [Fixtures] . Click [Fixturing on/OFF] under [Fixtures] . Then this option will change into
[Fixturing ON/off] . Thus the fixture simulator function is enabled (in this case, all the functions of the fixture
simulator are effective). In the default mode, this option is [Fixturing on/OFF] , indicating that the fixture function
is shut down.
Fig. 7.20 Enabling of Fixture Simulation Function
7.9.3 Port Matching
This function is used to transform the original measurement results into one characteristic determined by inserting
the matching circuit between the DUT and test port (one-port). The inserted matching circuit is selected from the
five preset circuit models or from the circuits defined in the double-port Touchstone file.