Novel, low-cost technique to manufacture submillimeter corrugated feedhorns

Corrugated feedhorns are commonly used with reflector antennas, either for emission or reception purposes, because of their very low side lobe beam patterns, their very good E-H plane symmetry and their important bandwidth. Unfortunately, the electroforming technique that is generally used to fabricate them requires the machining of a single use mandrel. Direct milling of the horn is also possible, either in a single block or in a split block, but this also requires to machine each desired horn. At submillimeter frequencies, machining of small corrugations in a mandrel or in a block is costly. We present in this paper a cost-effective technique to fabricate helicoidal corrugated feed horns, which consists in machining one reusable mandrel and to mold as many horns as needed.