In this work, a fuzzy hybrid approach (FHA) for the synthesis of rectangular microstrip antenna elements with thick substrates is presented. The FHA is based on a fuzzy genetic algorithm (FGA) and a controlled random search algorithm. The results obtained from the FHA are compared with the results obtained from the different types of genetic algorithm. The FHA gives a better design than the others. (C) 2000 John Wiley & Sons, Inc.