Analysis of CMRR in Doubly-Tuned Transformer Baluns

This work rigorously investigates circuit techniques that aim at increasing the common-mode rejection ratio (CMRR) in a transformer-based doubly-tuned balun network. The presented analytical results are able to predict and quantify the CMRR for various circuit solutions employed in the literature. Moreover, they are able to predict the conditions under which such solutions are not effective. Simulations performed on use cases of practical interest validate the developed theory.