A multi-polarization and multi-frequency single layer planar antenna

In this paper a novel single layer planar antenna, which simultaneously radiates circularly polarized waves and linearly polarized waves at two different frequencies for the mobile phone and ISM bands, is presented. Software simulations of the proposed design and associated measurements are reported as well. The presented antenna has the following features: (a) it is a single-layer electrically small planar antenna, (b) it radiates circularly polarized waves and linearly polarized waves simultaneously at two different frequencies by means of a single feeding port without the need of a phase shifter, (c) the radiation pattern is omni-directional. The antenna design shown in this paper can be easily applied to single layer printed circuit boards, which make the antenna very suitable for mobile phone and RFID applications.