CRLH mm-wave directional coupler on silicon substrate microprocessed by laser ablation

This work deals with the development and manufacturing of a Composite Right / Left Handed (CRLH) coupler structure for the millimeter-wave range. The device is made of CRLH artificial lines in a coplanar waveguide configuration (CPW). The device was processed on a 0.5 mm thick silicon substrate with a thermally grown 1 μm SiO₂ layer and a 3000 Å Au / 500 Å Cr metallization layer deposited on it. The silicon substrate offers the possibility of future integration in complex mm-wave circuits. The processing technology was laser ablation, known as a modern method for obtaining the device functional structure.