Comments to “Reactive Energies, Impedance, and Q Factor of Radiating Structures” by G. Vandenbosch

In an excellent paper [1], Prof. Vandenbosch derived rigorous equations for evaluating the radiated power and stored magnetic and electric energies explicit in terms of the source currents flowing on the radiating device. By integrating the radiated fields of an antenna it is easy to obtain the radiated power, but the evaluation of stored energies of a radiating system has been an issue since the early work of Chu [2]. The development presented in [1] involved advanced mathematics, however the resulting equations are easy to implement [3]. This letter shows simple alternative derivation of radiated power and stored energies, including the energy associated with the radiated field. The results of our approach produce exactly the same equations as presented in [1].