The effects of spherical conformity on a wideband L-probe circular patch antenna

This paper has described the theoretical design of a wideband circular L-probe patch antenna covering the ISM band of 2.4GHz. To increase the effective radiation area, the antenna is spherically conformed. To overcome the dielectric material cracking in the commercial microstrip due to the spherical distortions, an air dielectric is assumed, making the design of the antenna very simple and inexpensive. A grid pattern is overlayed on a planar 1.6mm thick commercial grade piece of aluminium cut to a circle with a radius of 100mm. This material is spherically conformed and the distortions measured to become the basis of the spherical conformal ground plane and the benchmark of the conformal element design. The different S₁₁ responses of the antenna are shown for different values of the element radius. The radiation pattern for the conformal antenna design shows an increase in the effective radiation area when compared to the flat antenna design. The conformal design also has a response similar to a λ/4 monopole with a maximum gain of 6dB.