By adding only one stub or by cutting one notch, CP can also be obtained, but then the configuration is not symmetrical.
However, as long as the total effective areas of these perturbations are of the same order,the performance of one edge modified is similar to that of a two-edgemodified square MSA.
The area of the stub or the notch is very critical to yield a lower AR value, just as in the case of a nearly square MSA, where
L1 /L2 ratio is very critical to yield CP.