Theoretical Study of Dipole Array of N Parallel Elements

The five‐term method developed for two arbitrarily located parallel antennas (Chang, 1967) has been successfully extended to a general antenna array of N parallel elements. The method can be applied to either planar array or three‐dimensional array. The array is characterized either by specifying driving voltages or input currents. Arrays of both half‐wave and full‐wave elements are discussed. The results reveal that the phase of the current along the antenna does not stay constant, as is generally assumed, even for arrays of half‐wave elements. As a consequence, differences between the actual computed field patterns and the ideal patterns computed by assuming sinusoidal currents are not negligible even in the main beam region. The input admittances of the elements vary widely from element to element. For the arrays of half‐wave elements, a complete analysis is also carried out with the conventional emf method. The results reveal the inadequacy of the emf method in dealing with these arrays.