Improvements in tapered slot antennas on thick dielectric substrates using micromachining techniques

The patterns of a tapered slot antenna (TSA) on a thick (93 mils, 2.36 mm) low dielectric constant substrate (/spl epsiv//sub r/=2.2) have been improved through micromachining techniques. A periodic hole structure was machined into the substrate to disrupt the formation of the dominant substrate modes. The measured directivity and main-beam efficiency of a 4/spl lambda//sub 0/ long TSA was increased as a result of the micromachining. We believe that this technique will allow the TSA to operate on a much thicker dielectric substrate needed for inexpensive and commercially viable operations-particularly imaging and power combining arrays at 60 and 94 GHz.