Approximating the Directivities of Antenna Elements and Arrays

The directivities of antenna elements and arrays (no mutual coupling included) is discussed. Replacing the directivity of the simulated or measured element pattern by a continuous function is needed here in order to improve the approximation of the directivity of the arrays. Two kinds of arrays are treated: a dipole array and a microstrip array. It is shown that the proposed method, based on the definition of the directivity, is more accurate than the simple formula based on the sum (in dB) of the directivity of the element and the directivity of the array factor (AF). Moreover, we show that the deviation of the directivity calculated by the proposed method from the simulated directivity is less than 0.5 dB.