ARBITRARY TERMINATION IMPEDANCES, ARBITRARY POWER DIVISION, AND SMALL-SIZED RING HYBRIDS

If a ring hybrid is terminated by arbitrary impedances, design equatio ns cannot be derived with conventional methods because symmetry planes for even-and/or odd-mode excitation are not available. Therefore, und er these conditions, new design equations for ring hybrids were derive d. They can be applied to ring hybrids with both arbitrary termination impedances and arbitrary power-division ratios. Also, new design equa tions for small-sized ring hybrids have been developed. They allow the design of arbitrary power division, arbitrary termination impedances, and especially small-sized ring hybrids. On the basis of these derive d equations, a theoretical evaluation was made using microstrip ring h ybrids, and experiments are demonstrated using a coplanar ring hybrid.