Yes, I am interested in things that enclose PCB's, when I took apart some waveguide stuff it looks like you needed a deep shaper machine and a lathe to make the square sides and disks, not to mention various plating technology to make the silver plate on the aluminum waveguide. This was just a cavity filter thing.
It does make me wonder if you can make waveguide out of welded stuff so long you have a very precise X-Y table on a very stable arbor press to use as a shaper, you can technically shave down the sides to parallelism, if you have a special tool that has scrapes on all 4 sides. It would be a lot of plunge cutting, I don't think a regular arbor press would be suited though. If you used thicker copper and solder instead of weld or braze it might not deform too much, so you might just need to shave a few hairs off, if you solder with spaces in place to ensure a consistent gap geometry, with minimum spacing between the parts (0.5thousanths maybe), since mechanical strength is irrelevant. It would be a nice machine if it can work because the travel would need to be like what, 3 inches?, and it would fit the same form as a drill press, so it would not occupy much floor space. It would only be hard if you need to make a big ass wave guide for like <2GHz. The tool would need to be long for for shaving copper or aluminum I doubt it would need to be very stiff? I imaging strait waveguide parts up to like 1.5 feet could be made that way, but hell if I know how to smooth out the interior of bends and stuff, maybe you could live with some irregularity there
The stuff-in-waveguide looks like you need a serious machine and chemistry shop. I do have a feeling from reading that so long you are under like 15GHz you can get away with significant butchery of waveguide geometry with little consequence
microwave101.com
"During the brazing and hardening process the walls of the waveguide can become deformed from their ideal geometry. At frequencies Ku-band and lower this tends to not be much of a problem;
a few mils of error represent less than 1% error and do not cause an appreciable effect on the insertion and phase of the signal at these frequencies. However, when reaching higher frequencies such a Ka, V, and definitely W, this becomes a problem worth thinking about when considering dip-brazing."
Taking some liberties with his numbers, I figure a rule of thumb might be 0.005 inches bulk geometric change = 1% error, since a few probably means 3 and 3 is less then 1 so we can make 1 = 5. Engineering math. Might be as high as 0.01 inches.
I have some avionics waveguide for around the Ku band, I wish I had a CMM to see what was considered acceptable for its manufacture. I doubt a micrometer will give me terribly useful information but I will give it a whirl. 5 thousandths is not that crazy accurate. Low melting point soft solders might make this really achievable. 1% of a high power signal is like 1dB. For 10GHz thats in the same ballpark as RG141, which is like 0.6dB/Foot @ 10GHz, wheras commercial WR90 waveguide is expected to have something like 0.03dB/foot. I wonder what he means exactly. If he means error from the ideal target specification, then we are golden, since 1% of 0.03dB is basically nothing. Who gives a shit if its 0.03dB +- 1% ?? Its still a dead short compared to anything else you can do. I doubt anyone here can even measure better then 0.05dB @ 10GHz anyway, unless they work for Lecroy or Agilent.
I think I have seen hybrid cavity filter/PCB enclosure thing inside of a spectrum analyzer, but I never took apart the cavity filter bit, It's the part where you use screws to adjust little 'pistons' to tune the thing right?