Radiation properties of single-layer multiband rhombic MSA with slots

This paper demonstrates a novel multiband rhombic microstrip antenna (MSA) with multiple slots printed on a single-layer PTFE substrate. The antenna is fed by a coplanar gap coupled with a V-shaped patch. Three inverted V-shaped slots are assumed on the rhombic patch and hence four resonant frequencies are obtained. Broadside radiation patterns and gain of over 5.0 dBi are also obtained. Experiments were carried out to verify the results estimated by IE3D simulator. Good agreements between simulated and measured results are confirmed. To further evaluate the performance, rhombic MSA with six inverted V-shaped slots is also investigated. Again, this antenna model accomplishes excellent multiband performances over the seven observed frequencies. Thus, the rhombic MSA with multiple slots is well suited as an alternative design for a multiband planar antenna.