Modelling the distortions to manufacture spherical conformal microstrip antennas

In modern living, there is enormous emphasis on any commercial product to not only perform, but to look good as well. In some cases, the antenna is often perceived as being ugly in the eyes of the consumer, particularly if it protrudes from the device or object that features a curved surface. A typical example is the antennas located on a future modern vehicle to access the future multimedia services (T. Talty et al., Ant. and Propag. Soc., IEEE Int. Symp., vol. 1, pp. 430-433, 2001). In these applications, antennas have to conform to a spherical or pseudo spherical surface to mask their presence. These types of surfaces present problems when microstrip patch antennas have to conform to them. Typically, microstrip antennas are designed for a planar surface. Conforming them to a spherical surface introduces distortions to their shape. This paper outlines a method based on experimental data of predicting how a simple planar wideband L-probe fed patch and its ground plane will distort when spherically conformed. A method of predicting the new design of the spherically conformed patch antennas is given so that its performance can be modelled accurately.