Till now

the theories of Microwave open resonators are almost to calculate the electrical parameters at resonace by assuming that the geometry of the cavity is given. In this paper

from the fundamental theory of microwave open resonators a simple and convenient inverse design method is proposed. Analytical formulae for calculating its geometrical parameters

as well as charts of the calculated results

are given.Calculated electrical properties for some high Q cavities designed by this method are in good agreement with those expected

and for medium Q cavity the results are within the accuracy of 10-2.