A method for designing broad-band microstrip antennas in multilayered planar structures

The narrow bandwidth of a microstrip antenna is one of the important features that restrict its wide usage. A simple and practical method for the design of broad-band microstrip antennas is presented in this paper. Utilizing this design technique, several two-layer microstrip antennas have been proposed. To confirm the applicability of the method for the designs of antennas at L-band, experiments have been carried out. The measured results show that the proposed antennas have a bandwidth of up to 25.7%. Also, the method proposed in this paper is applicable to the design of other types of multilayered planar antennas.