A Note on the Characteristics of the Two-Antenna Array

The definition for the "effective length" of a transmitting antenna, which was recently brought to the attention of PROCEEDINGS readers, is used in deriving expressions for the radiation function, radiation resistance, directivity, and gain of a two-vertical-antenna array, when the relative phase of excitation and current amplitudes are of arbitrary value. The formulas derived for computation of the array characteristics are so simple that they may be applied by anyone having a rudimentary knowledge of antennas and mathematics. Since the assumption of a perfect earth is made, the results are precise only for antennas operated at broadcast frequencies, and at longer wavelengths.