A novel approach for analysis of cavity

An efficient technique using the fast Fourier transform, sum algorithm and Pade approximation, in combination with the finite-difference time-domain method, is presented for computing the resonant frequencies of a cavity. Without sacrificing the accuracy of the results, this new technique significantly reduces the computational time and the possibility of modes missing in comparison with the conventional FFT algorithm. The resonant frequency of rectangular cavity is computed, and a comparison is made to validate the utility of this technique.