Suppression of surface waves using the micromachining technique

Silicon micromachining has been applied to build high performance microwave and millimeter-wave antennas. To suppress substrate modes and increase the bandwidth of the patch antenna, silicon substrate material has been selectively removed under the patch area. It has been shown that the new structure can effectively suppress unwanted substrate and higher order modes. Also, effective dielectric constant curves for micromachined substrates are provided for accurate design of patch antennas.