In an earlier paper, the use of a "thru-short-delay" (TSD) technique for calibrating the dual six-port automatic network analyzer was described. Another scheme required only a length of precision transmission line and a "calibration circuit." The better features of these two somewhat different approaches have now been combined and the requirement for either a known short or a "calibration circuit" eliminated. This paper will develop the theory for this new procedure.
Glenn F. Engen, Cletus A. Hoer, "'Thru-reflect-line': An improved technique for calibrating the dual six-port automatic network analyzer," IEEE Transactions on Microwave Theory and Techniques, vol. 27, no. 12, pp. 987-993, December 1979.
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