The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (epsilon(r) = 3.9, tan delta = 0.0002 at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing similar to 15% bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average similar to 6.4 dB) in the broadside direction over the entire WiGig band.

Peer Reviewed