Systematic methodology for cylindrical structural antenna design
Authors:
Raphael Notter, Sylvain Collardey, Ala Sharaiha, Loïc Bernard, Philippe Pouliguen, Paul Karmann
Abstract:
This paper presents a methodology for the design of cylindrical structural antennas that operate using radial
modes, making them efficient radiating elements. These antennas are directly integrated into cylindrical
structures making them suitable for aerospace and automotive applications. The proposed approach enables the
excitation of such a structure with a low-profile source and benefits from a larger resonant surface. A major
challenge of these antennas is the appearance of higher-order modes when the structure’s size becomes large
compared to the wavelength. However, radial modes remain largely unaffected by the cylinder’s length, making
them particularly advantageous. To address this, we propose a novel method to excite radial modes on
cylindrical structures with different radii and lengths. First, Characteristic Modal Analysis (CMA) is used
to select the desired and undesired modes. Next, the excitation of these modes through slots is analyzed and
optimized, followed by the feeding design using coaxial probes or aperture coupling feeding. Additional
improvements such as parasitic slots are also explored. Different models are presented and simulations are
conducted using a 3D full-wave solver. Prototypes for various sizes were fabricated. The results demonstrate
that this approach enables seamless antenna integration into various cylindrical structures without
compromising electromagnetic performance, even when the structure is significantly larger than the wavelength.
This work highlights the potential for multifunctional systems.
