Printed Conformal Antennas Design

In many applications pertaining to missile, satellite, spacecraft and aircraft a directive antenna mounted on a curved body is required. Conforming the antenna to the surface save space and is often essential for structural reasons. An antenna that conforms to a surface whose shape is determined by considerations other than electromagnetic; for example, aerodynamic or hydrodynamic called conformal Antenna. Microstrip antenna technology is most suitable for conformal applications because of their ability to conform to non-planar structures. Microstrip antenna patches are placed above what may be characterized as a conducting plane with a dielectric substrate separating the patch from the conducting plane. The properties of such an array depend strongly on whether it is small compared to the radius of curvature of mounting body, in which case it behaves nearly like a planner array or whether it is comparable or large to the radius.

Conformal antenna may be put in the belly of aircraft then there is no need of radome. Besides this, shaping and resolution can be improved by using conformal antenna as more elements can be accommodated. In conformal antenna it is found that resonance frequency is same for various curvatures. However as curvature increases the pattern broadens. The aperture design of the conformal array is predicted on the knowledge of the patterns and coupling coefficients in the mutual coupling environment. The analysis and synthesis of conformal array is slightly more complicated than linear array with uniform spacing because the array elements point in different directions.

Details: In Book "Practical Microstrip and Printed Antenna Design"