| 20120109566 | METHOD AND APPARATUS FOR CALIBRATING A TEST SYSTEM FOR MEASURING A DEVICE UNDER TEST - A calibration method for a two-port VNA includes presenting a high reflection calibration standard and measuring reflection data for each of the two ports, calculating a location of the high reflection calibration standard at each of the two ports, presenting a load calibration standard and measuring the reflection characteristic for each of the two ports to provide load data, converting the load data to the time domain to provide time domain impulse response load data, and gating the time domain impulse response load data based on the locations of the high reflection calibration standard at each of two ports. The method further includes reconstructing frequency domain load data from the gated time domain data, connecting the two ports together and determining forward and reverse transmission characteristics, and calculating systematic error coefficients for the VNA based on the reconstructed frequency domain data and the forward and reverse transmission characteristics. | 05-03-2012 |