On the Radiation Resistance of a Simple Vertical Antenna at Wave Lengths below the Fundamental

In this paper, the radiation resistance of a filamentary vertical antenna erected over perfectly conducting plane earth is calculated for wave lengths down to 0.3 of the fundamental. Pierce's assumption of sinusoidal variation of the current amplitude along the antenna forms the basis of an application of the methods of the electron theory, whereby the e.m. potentials are found by integration and the field and Poynting vectors subsequently derived by differentiation. An improved method of computation, using the sine- and cosine-integrals, is introduced. The numerical results are tabulated and exhibited graphically.