Micromachined 40 GHz post-supported patch array using thick SU8 photoresist

A 40-GHz coplanar waveguide (CPW)-fed post-supported patch antenna is presented using a modified fabricating method. The radiating patch is based on a quartz glass (SiO₂) and the CPW feed line is based on silicon (Si) substrate. The post is constructed by SU8 photoresist with the thickness of 250 μm. Flip-chip method is used for the connection of the two parts. Compared to traditional designs, most of the complex CPW feed line network on Si substrate is replaced by the microstrip line based on SiO₂ in the proposed structure, which reduces the losses caused by the Si substrate used in CMOS technology. Preliminary measurement on return loss and radiation pattern is presented.