Closed-Form Expression for the Directivity of Circumferential Conical Microstrip Antenna Arrays

This paper introduces a closed-form expression for the directivity of circumferential conical microstrip antenna arrays, offering a valuable resource for their analysis and design. The proposed expression eliminates the need for time-consuming numerical integration over the radiation sphere. By employing the magnetic current model and orthogonality relations for the associated Legendre functions, we evaluate the power radiated by the array through an analytical formula. Comparisons with directivities obtained using HFSS software demonstrate the accuracy of the derived expression.