On the Application of a Novel Laser-Based Rapid Prototyping Process for Planar Antenna Elements

Miniaturization challenges and complex geometries of antenna equipment for mobile communications are drivers for the design and the implementation of novel fabrication processes with enhanced exactness. Furthermore, the antenna designer requires fabrication processes that provide an accurate and fast transformation of his layout into a prototype in order to cross-check the simulation results. This paper describes the employment of a novel laser-based manufacturing process for rapid RF PCB prototyping that provides a fast, cost-effective and accurate solution to meet all these requirements. The process is based on a new laser direct structuring method avoiding RF substrate damaging of conventional laser processes. At the same time a maximum resolution of 50 mum lines and 25 mum spaces can be achieved. This process is used for the prototype realization of complex planar, symmetrical log.-per. antennas that are characterized with respect to their impedance- and radiation behaviour. The geometric precision of laser structured antenna features is characterized and compared to the results achieved with a conventional photolithographic process as well as to simulation results derived from the finite-element method