TABLES OF NORMALIZED CUTOFF WAVE-NUMBERS OF ELLIPTIC CROSS-SECTION RESONATORS

Current methods to evaluate the mode resonance of elliptic cross secti on resonators are cumbersome for design purposes. In this paper, table s for the cutoff wavenumbers of TE(nm) and TM(nm) modes for both even and odd modes are tabulated in a new way, that reveals a simple relati on to the equivalent circular cross section resonator and makes interp olation results accurate. These tables range for n = 0, ..., 3 for eve n modes and n = 1, ..., 4 for odd modes, with m = 1, ..., 5 for both. The tables cover 80 different modes for eccentricity in the range 0 le ss-than-or-equal-to e less-than-or-equal-to 0.99. Asymptotic formulae are given for higher modes and approximate formulae are given for smal l eccentricity 0 less-than-or-equal-to e less-than-or-equal-to 0.2. Th e accuracy of interpolation, approximate formulae and asymptotic formu lae are compared with published results.