Micromachined antennas with reduced effective dielectric constants

The objective of this work is to illustrate the capability to develop low cost microstrip antennas that offer improved performance on high dielectric materials by locally reducing the effective dielectric constant. Typically, patch antennas exhibit poor performance on high index materials due to pronounced excitation of surface waves. This paper presents the development and characterization of a microstrip antenna that has been fabricated using Si-based micromachining techniques. Two antennas are designed to operate at similar frequencies where one is implemented on a full thickness silicon substrate while the other is formed on an silicon-air substrate that has a 1:1 thickness ratio. The design and testing procedures are described herein, followed by measured results of the antenna performance.