Backward Unknown-Thru Calibration Method

A useful calibration method utilizing the SOLR, ‘Unknown Thru’, is introduced. The proposed method is expected to be very useful for the applications where long cables should be used with a VNA such as antenna measurements. With the proposed method very long or lossy cables can be used as long as one-port calibration can be carried out at the cable ends. Compared to the classical SOLR it has much larger signal-to-noise ratio at the ‘Unknown Thru’ measurement stage of the calibration process.