Microstrip patch antenna using silicon micromachining technology

The design of a 20 GHz rectangular microstrip patch antenna over micromachinated silicon substrate has been performed using HFSS®. The micromachining technique has been used to synthesize a low dielectric constant region in the silicon substrate. In this technique, silicon is partially removed underneath the patch antenna, forming a mixed air-silicon region is controlled to synthesize a predetermined value. The microstrip patch antenna over the micromachined silicon substrate shows better bandwidth with respect to that over Duroid substrate. An improvement of 40% in bandwidth is obtained for an 80% silicon removal. The effect of silicon conductivity has been studied and it has been showed that silicon conductivity enhances the antenna bandwidth at the expense of reduced efficiency.