An Improved Frequency-Independent Reaction Using Equivalent Dipole-Moment Method

Abstract

The frequency-independent reaction (FIR) is improved by using the equivalent dipole-moment (EDM) method. The FIR is a fast frequency sweep technique based on the Taylor series expansion, where the exponential of Green function is expanded as the Taylor series. The matrix element becomes the series summation, where each term is the product of the geometric components that are computed once and the phase factor that must be computed at each frequency. The matrix can be efficiently generated by using the FIR. However, the memory requirement is large. The geometric component generation is still time consuming. In this paper, the far-field computation is accelerated by using the EDM method. In the EDM method, the testing and source function pairs are equivalent to an infinitesimal dipoles. The matrix element is the multiplication of the electric field radiated by the source dipole and the moment of the testing dipole. Comparing with the FIR, calculation of matrix element can be greatly simplified. A Numerical example is implemented. Simulation results show that the results of the proposed technique agree well with those of the FIR. Both the CPU time and memory cost are reduced by using the proposed technique.