A UNIVERSAL RING 0°/180° COUPLER FOR ARBITRARY POWER DIVISION

摘要

A universal ring structure is presented for the 0°/180° coupler operation with arbitrary power division ratios. The ring circuit topology is investigated for the 0°/180° coupler operation based on the 4-port admittance parameter analysis. The universal design equations are derived in terms of 4-port admittance parameters of the coupler and the 2-port branch parameters of the ring. The universal conditions for the coupler operation are presented in terms of the self and the mutual admittances of the ring. The universal ring topology under consideration is quite general with minimized circuit restrictions and the presented results are applicable to almost all types of ring coupler structures including the lumped as well as the distributed circuit implementations. As an example, the presented results for the universal ring are applied successfully to the design of uniform transmission line ring couplers with arbitrary values for the line impedances, electrical lengths, and the power division ratios.