An investigation of radiation from extremely thin planar antennas using characteristic mode analysis

Summary form only given. Microstrip antennas are one of the most widely used antennas in wireless applications. Increasing demand for miniaturization means that microstrip antennas not only scale in area but also in thickness. When the microstrip patch is placed in close proximity of the ground plane, most of the energy is stored in the form of parallel plate modes between the two conducting regions. Parallel plate modes store energy between the antenna and the ground plane and lead to the decrease in gain and an increase in cross-polarization levels. Parallel plate modes are thus considered to have a detrimental effect on the radiation characteristics of microstrip antennas. However, if used intelligently, radiation can be encouraged from the parallel plate modes.