I. Theoretical deduction h Resonance frequency 0=C丌 =2/ In a cubical resonant cavity: o=Cx q vm+n+p n=2a/vm+n+p Discussion of degree of degeneracy Define: n 2 +n2+p2=X 1 3 the degree of degeneracy is 1 2.m2 A,P2=B(2A+B=X, A+B), the degree of degeneracy is 3 B,p2=C(A≠B≠C,A+B+C=X),the degree of degeneracy is b;I. Theoretical deduction Resonance frequency: In a cubical resonant cavity: Define: Discussion of degree of degeneracy: 1. , the degree of degeneracy is 1; 2. , the degree of degeneracy is 3; 3. , the degree of degeneracy is 6; 2 2 2 2 2 2 m n p c a b d   = + + 2 2 2 2 2 2 2 / m n p a b d  = + + c 2 2 2 m n p a   = + + 2 2 2  = + + 2 / a m n p 2 2 2 m n p X + + = 2 2 2 3 X m n p = = = 2 2 2 m n A p B = = = , (2 , A B X A B + =  ) 2 2 2 m A n B p C = = = , , ( A B C A B C X   + + = , )