Fig 1.
Analytical model of UCA.
Fig 2.
Characteristic current distribution at 3.55 GHz.
(a) TM41 degenerate modes (b) TM61 degenerate modes.
Fig 3.
Schematic design of antenna and uniform circular array (a) unit element (b) uniform circular array, (c) impedance characteristic of array, where b1 = 27mm, b2 = 40mm, a1 = 25mm, a2 = 4.5mm, a3 = 18mm and a4 = 9.5mm.
Fig 4.
Simulated phase and amplitude distribution of the proposed antenna (a) simulated phase and amplitude for element, (b) resultant simulated phase and amplitude for array.
Fig 5.
Simulated co-polarization and cross-polarization radiation patterns of the proposed antenna.
Fig 6.
Simulated axial ratio of the proposed antenna at both orthogonal planes.
Fig 7.
Mode purity (a) for element (simulated) (b) for array (simulated) (c) for array (measured).
Fig 8.
Fabricated Prototype and measurements (a) s-parameter measurement setup (b) far field setup (c) reflection coefficient (d) axial ratio (e) E-field phase (f) E-field amplitude (g) far field pattern.
Table 1.
Comparison of the proposed UCA with reported designs.