Attainment of Circular Polarization in Planar Patch & Conformal Patch Antenna using Ring Slotted Ground Plane
Abstract
A square Patch Antenna in planar and conformal surface with circular polarization are proposed. Both the antennas are designed on two kinds of substrates that is FR- 4 epoxy and air. Two circular rings having symmetrical dimensions are slotted into the diagonal of ground plane in a planar surface as well as curved surface.
Both antennas are designed and fabricated on FR- 4 and air. The reason for considering air substrate is that FR-4 is too hard to design. During bending, it may break.
Both antennas respond differently at a frequency of 1.80 GHz. Simulated AR bandwidth for planar antenna with FR-4 and air substrate are 14 MHz and 15 MHz respectively with impedance mismatch (S11) bandwidth are 63 MHz and 89 MHz respectively.
Similarly simulated AR bandwidths of conformal antenna with same substrates as above are 6 MHz and 17 MHz with impedance bandwidth 83 MHz and 96.6 MHz respectively.
The gain of planar antenna of FR-4 substrate and air substrate are 3.94 dBi and 8.77 dBi with AR axial ratio beam width 173.420 and 164.390 and that for air substrate, the 3 dB AR beam width 104.09 degree and 99.47 degree in E-plane & H-plane respectively.
The conformal antennas of FR-4 substrate and air substrate have gain 3.72 dB and 8.35 dB with 3 dB axial ratio beam width 173.44 degree and 172.27 degree and 100.23 degree and 73.6 degree in E-plane & H-plane respectively.
For air substrate in planar design the antenna delivers good results at a frequency of 1.8 GHz. The 3-dB Axial Ratio was simulated at 15 MHz, with Impedance Bandwidth at 89 MHz. The gain at phi=0 and phi=90 degrees was 8.77 dB.
