A method of making a structured surface and a mechanical fastener precursor are disclosed. A terminal in a satellite communication system may receive a first communication signal in a first polarization and a second communication signal in a second polarization substantially orthogonal to the first polarization. The rotational kinetic energy is then stored as elastic energy of the spring. The rotating operation of the trigger requires power smaller than an operation for directly pushing and drawing the piston rod by hand. Each fourth order low-pass and high-pass filter is composed of a cascade of two second order low-pass or high-pass filters, respectively, and each second order filter has the same cut-off frequency and Q factor as the corresponding shelving filter. Each beam is optically coupled to a photo detector which translates its power into an electric current.