Micromachined patch antennas on synthesized substrates

This paper presents the methods which obtain synthesized substrates in a silicon wafer. One of methods is that cavity is etched by silicon micromachining technique, then filled with lower permittivity materials, such as silicon dioxide or polyimide. The other method is that synthesized substrate is achieved by us micromachining to remove a portion of the silicon material from underneath the specified cavity region resulting in two separate dielectric regions of air and silicon. The designs of planar antenna structures based an above several synthesized substrates are presented, and their resonant frequencies, return loss and bandwidth are evaluated and measured.