An Improved De-Embedding Method for Low-Loss Reciprocal Fixtures

This study proposes an improved version of an existing de-embedding method that combines the amplitude symmetry of reciprocal lossless networks with time-domain truncation. In the proposed method, parameter S11 is still obtained by a time-domain truncation method. And in contrast to the original method, there is no need to compute the phase delay of the fixture to determine the phase of parameter S21. Instead, a new microstrip line phase delay formula was derived by introducing the magnitude-symmetry formula of reciprocal lossless networks, which was then used to determine the phase of the fixture’s parameter S21. The accuracy of the derived phase delay formula was verified through simulations. The simulation analysis confirmed that this formula is applicable to lossy networks. The simulation results also show that the proposed improved method simplifies operation and reduces measurement steps compared to the traditional de-embedding methods while maintaining high accuracy and feasibility through simulations. The proposed method can also achieve better de-embedding accuracy in the high-frequency range than the original method.