Comments on "A rapid evaluation technique for functional Gunn diodes"

In a recent paper, Larrabee et al. proposed the magnetoresistance measurement for a quick determination of electron mobility in a functional Gunn diode. It is pointed out in this correspondence that the formula used in the paper is applicable only to extremely thin Gunn diodes where the length-to-width ratio is negligibly small. It is also shown how to obtain the correct value of the mobility by taking the geometry effect into consideration.