Property Analysis and Experimental Study of the Broadband Transmission-line Transformer in Multimode Feed Network

摘要

Transmission-line transformer are useful circuits for microwave impedance matching applications due to theirbroad operating bandwidth. Multimode feed network, composed of two substructures which are deviced on the transmission-line transformer. Beginning with the broadband transmission-line transformer with 4:1 impedance transformation, bysupposing the currents on the two lines are not equal but opposite and with the application of two line transmission-linetheory, the current-voltage relationships of the asymmetrical (current) bifilar even transmission line are obtained????Itsequivalent model with mutual coupling between transmission-line taken into account is given, and its characteristics forimpedance transformation is analyzed. It also gives a useful and effective analysis method for bifilar transmission-linetransformer. The calculated values are in good agreement with the metrical values????so in real application it can better improvethe performance of the component and can be used more efficiently.