High-yield narrow-band matching structures

The circuit yield for commonly used narrowband microwave (bandwidth less than 5%) lumped- and distributed-parameter matching structures is evaluated. It is found that yield is a function not only of the matching structure but also of the load impedance. The lumped-structure yields are analytically determined using an elliptic approximation technique which gives a closed-form solution to the high-yield structure choice problem. Sensitivity issues are discussed. A simple design chart which helps the designer choose a high-yield matching structure for a given load impedance is developed. Two examples illustrate its use. Structure choice in one example changes the yield from 61% to 84%. >