Effects of the Length of Thru on the Measurement Precision in TRL Technique

The effect of the length of Thru on measurement precision in Thru-Reflect-Line (TRL) technique is investigated for the first time. Additional error matrices are introduced to represent random connection errors caused by soldering the adaptors and the test fixture. The simulated results show that the length of Thru periodically reduces the effects of connection errors on measurement results, and the length of Thru causing minimum error varies with the impedances of devices under test. The results are verified by experiments in which the copper tape is used to emulate and enlarge randomly distributed connection errors.