Ground plane PBGs and their effects on the performance of microstrip patch antennas

Microstrip antennas are known for their advantages in lightweight, low volume, low cost, and compatibility with integrated circuits. These advantages make this antenna a useful candidate in applications such as mobile radio, satellite communications, biomedical radiators and feed elements for reflectors. An important factor in the performance of microstrip patch antennas is the ground plane. The size of the ground plane has a significant effect on the radiation pattern and the gain of the patch antenna as reported by S. Noghanian and L. Shafai [1]. In addition to the size of the ground plane, it has been shown that by etching holes in the ground plane one can control the excitation of certain modes of a microstrip patch antenna [2]. In this paper, the effects of perforations in the ground plane on the performance of narrow band and wide band patch antennas are studied. It is shown that by placing a hole or multiple holes in the ground plane of a simple patch, one can cause a shift in the resonance and an increase in the bandwidth of the antenna. In addition, placing slots in the ground plane of a narrowband microstrip can create a frequency shift of the higher modes and in the case of a wide band antenna an increase in the bandwidth.