Analysis of Circular Polarization of Cylindrically Bent Microstrip Antennas

Figure 9

The 3dB axial ratio area (shaded) in the main beam. Radial coordinate is 𝜃=0⋯80^∘, polar 𝜙. Main lobe direction is 𝜃=0. The figures are best understood as a map of the polar region of the spherical coordinate system. (a): almost flat antenna, shown both 3D and in (𝜃, 𝜙) coordinates. (b): 80 mm and 60 mm radii.

(a)

(b)

(c)

(d)