Cylindrical-rectangular patch on fiber-enhanced composite ground plane

Patch resonators flush-mounted on cylindrical structures such as space vehicles, missiles, airplanes have been used as antenna elements. Composite materials have been widely used in modern aircraft and vehicle surface designs to reduce weight or radar cross section. Take for example, a graphite/epoxy composite is made of several laminae of epoxy resin with conductive graphite fibers embedded in specific directions. The fiber spacing in each lamina is much smaller than a wavelength, hence each lamina can be modeled as an anisotropic layer with a conductivity tensor. Layers of different fiber orientations are stacked to enhance the mechanical strength. Planar laminates can be wrapped to form a cylindrical structure. Conventionally, the ground plane of a resonator is modeled as a perfect electric conductor. If a patch resonator is built on composite surfaces, the resonance properties will be different from those obtained by the perfect conductor assumption.