Enhanced patch-antenna performance by suppressing surface waves using photonic-bandgap substrates

TLDR

Microstrip patch antennas are low‑profile, inexpensive, and support diverse radiation patterns, yet they suffer from limited bandwidth, low gain, and surface‑wave losses that reduce efficiency. The study proposes a photonic‑bandgap substrate to reduce surface‑wave effects in patch antennas. The authors analyze a thick‑substrate configuration to evaluate the substrate’s performance. The PBG patch antenna exhibits markedly lower surface‑mode levels, leading to higher gain and improved far‑field radiation patterns.

Abstract

The microstrip patch antenna is a low-profile robust planar structure. A wide range of radiation patterns can be achieved with this type of antenna and, due to the ease of manufacture, is inexpensive compared with other types of antennas. However, patch-antenna designs have some limitations such as restricted bandwidth of operation, low gain, and a potential decrease in radiation efficiency due to surface-wave losses. In this paper, a photonic-bandgap (PBG) substrate for patch antennas is proposed, which minimizes the surface-wave effects. In order to verify the performance of this kind of substrate, a configuration with a thick substrate is analyzed. The PBG patch antenna shows significantly reduced levels of surface modes compared to conventional patch antennas, thus improving the gain and far-field radiation pattern.