Patent Document ID: 9897681
Application ID: 14635698
Patent Flag: 1

Claim One:
1. A calibration method for a radio frequency (RF) test apparatus for testing an RF device under test (DUT), the method comprising: providing an RF test apparatus having a plurality of channel terminals, a calibration board having a plurality of board terminals and a first amount of cables, wherein each of the cables is connected with its first end side to one of the channel terminals of the RF test apparatus and with its second end side to one of the board terminals of the calibration board, the calibration board comprising an internal connection circuit for providing a second amount of connections within the calibration board such to provide a second amount of connection loops between the channel terminals of the RF test apparatus, wherein the second amount is greater-than-or-equal to the first amount; setting up an equation system for calculating the attenuation for each of the second amount of connection loops; measuring the attenuation for each of the second amount of connection loops; measuring the attenuation for each of the second amount of connections on the calibration board; determining a first amount of attenuations of the cables by solving the equation system; and providing a path correction prior to starting a test process for every individual cable connected to corresponding channel terminals of the RF test apparatus based on the determined attenuations of the cables.