Radiation and scattering from arbitrary microstrip etches

The radiation and scattering from arbitrary microstrip etches are analyzed using the moment method in the spectral domain. For each strip segment, the currents are expanded in terms of a set of basis functions in the local tangential and normal coordinate system to easily incorporate their proper physical behavior. The known numerical difficulties associated with the dyadic Green´s function´s singularities and poor asymptotic behavior are addressed. Techniques for avoiding these singularities during the numerical integration and improving the rate of convergence of the moment method´s inner products are discussed. Models for the feeds, bends, and impedance termination of the microstrip lines are examined. Finally, representative results for both the scattering from printed circuits and the radiation from probe-fed microstrip lines are presented.<>