Asymptotic method in prediction of E plane radiation pattern of rectangular microstrip patch antennas on finite ground

Limited ground effect on the radiation pattern of microstrip antenna is already known. A simple method to predict E plane radiation, except in the neighbourhood of the geometrical optical boundary that is theta =90 degrees , is presented. A very good value of the field on this boundary is given: it means that the leaving pattern could be constructed by interpolation. Good agreement is obtained between the theoretical results and the experimental measurements in the validity domain of the method.