On the Calculation of Radiation Resistance of Antennas and Antenna Combinations

It is shown that there are two methods for calculating the radiation of antennas and antenna systems. One depends on the consideration of the electromagnetic field produced by the radiating system, that is, on the integration of the Poynting vector over a surface enclosing the system. The other is based on a consideration of the electromagnetic phenomena on the conductor itself. The identity of the two methods is demonstrated. The second method is much simpler to treat formally and gives clearer results. The calculation of the radiated power is especially simple, using a law that provides a connection between the radiated power and the Hertzian vector for the system under consideration. This hitherto unknown law is derived. The radiated power of any arbitrarily loaded antenna and of short-wave antenna systems with parallel elements is calculated by means of this law.