Circularly polarized patch antenna matched to liver tissue with optimum placement positions

In this paper, a circularly polarized microstrip patch antenna matched for propagation in microwave liver tissue is designed at 2.45 GHz. The reflection loss of the antenna is less than 10 dB from 1.8-2.6 GHz. The antenna is circularly polarized in elevation plane cut at azimuth angle (ϕ) of 90°, for elevation angles (θ) from −14° to −7° and from 11° to 17°. The axial ratio is below 3 dB in this range of angles from 2.2-2.7 GHz. So considering any reference antenna inserted in the liver tissue, the designed antenna can be placed in any orientation on the liver surface at one of these angles which hold the circular polarization.