Ku-band slot array antennas for low profile mobile DBS applications: printed vs. machined

Slot arrays fed with post-wall waveguides were fabricated using conventional printed circuit substrates. Side-walls of waveguides are emulated using rows of closely spaced vias. These arrays have been investigated and compared to the previously developed conventionally machined slot arrays that are defined on top of standard metallic waveguides. Fabrication costs of printed slot arrays are much less than that of machined ones. Additionally, a tolerance of up to 2 mils can be easily realized by using a chemical etching process. However, the insertion loss of printed slot arrays is relatively high due to the dielectric substrate loading. Nevertheless, these antennas, if integrated with LNAs, would sustain the high performance feasible of typically all-metallic slot array structures