A Novel Analytical Method for Multi-Frequency Transmission Line Transformer

A novel analytical method for transmission line transformer is presented, which is based on small reflection theory and can be applied to multi-frequency transformer with arbitrary frequency ratio in certain range. Particularly, comparing with transformer based on transmission line theory or ABCD matrix method, the proposed method is much easier to be extended to the transformer with more than triple frequencies. To validate the proposed method, a penta-frequency transformer is implemented and measured. The measured results are consistent with the calculated and simulated results.