• Tinus Stander
    0
    Hi everyone!

    We're planning some experiments on AM'ed waveguides, and I just noticed that our WG cal kit uses a flat, square WR42 flange (FBP).

    Is it worth printing a choke on the DUT's flange? We're not pressurizing, of course, but if the performance degradation from mating two flat flanges is significant, we might need to consider it seriously.

    t
  • madengr
    0
    I had some WR-15 and WR-10 AM waveguides made on the Protolabs AlSi10Mg high-res process. I did not use a choke but I did have the flanges polished; they will do that.
  • Tinus Stander
    0
    Sounds promising! An no significant loss across the flange connection?
  • madengr
    0
    The WR-15 worked well. For a 3” length, the insertion loss was 0.3 dB, compared to 0.2 dB for the 3” reference. The WR-10 did not work well.

    The surface roughness models in the 3D simulators do not work well; they overestimate the loss for the rather rough surface.

    I had previously stated the flange was polished. It was just machined flat. I suppose you could polish it, but the machining is probably adequate.

    I don’t know how high-Q structures would perform. I’d like to make a WR-15 filter or resonator; just no time.
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