The edge effect of planar phased hexagonal arrays is numerically investigated by comparing exact solutions of active impedance and array element pattern of finite arrays with those determined with infinite array approximation. The analysis incorporates the improved circuit theory, which has a higher accuracy than the electro‐motive‐force method. Considerations are also made for the edge effect on the total array pattern. It is found that the edge effect is in reverse proportion to array size. It can be neglected for arrays composed of more than 200 elements, for which the array pattern can be well approximated by the product of the array factor and array element pattern of an infinite ar