Numerical analysis of the microstrip printed dipoles

The moment method in the Fourier‐transformed domain has been used widely as a rigorous numerical method for analysis of patch antennas, microstrip lines, finlines and planar circuit structures. In this paper, this method has been applied to a planar printed dipole on the grounded dielectric substrate. The integrand in Sommerfeld‐type integrals with a slow convergence rate has been modified by means of an effective dielectric constant determined from the asymptotic values for large spectral components so that the convergence can be improved significantly. The method of computing the matrix elements in the moment method, evaluation of the effective radius of a planar dipole and separation of the radiated power and the surface wave power are discussed. Finally, the validity of the method is confirmed by comparison with measured data. In addition, the effect of the substrate thickness on the antenna performance is discussed.