Improvement of the Characteristics of the Simple-loop Hybrid Ring Based on the Image Immittance Theory

A way to improve the frequency characteristics of the simple-loop hybrid ring is considered explicitly according to the image parameter theory extended to the (n, n)-port. The compensation may be classified by the degree of the approximation of the image admittance at the operating frequency. The first compensation is due to the approximation of the image admittance to λ＾＜−1＞ and the second to λ＾＜−2＞. By these methods the compensated circuits are gotten theoretically and the hybrid characteristics of these circuits are shown