[Microwave] testing waveguide coax transitions

[Steve]

At 03:50 PM 10/31/2016, Dr. Gerald N. Johnson wrote:
>It is hard to predict how a WR75 transition and load made 
>specifically for 13 GHz will work at 10 GHz though 10 GHz is in the 
>standard working range of WR75. The match depends so much on the 
>probe location and dimensions, and its easier to make it narrow band 
>that full waveguide band.

You could bolt several of the WR75 transitions together then sweep 
them through 10 GHz. If they show relatively low loss, you could 
assume they most likely have fairly low loss...  at least, lower 
than, say, -6 dB at 10 GHz. Personally, I would not trust a 
transition showing more than perhaps 0.3 dB loss (individually) at 10 
GHz. In fact, I would not trust a WR-75 transition at 10 GHz without 
full characterization. I would assume it'd present a few dB, at the 
minimum, additional loss down at 10 GHz, and I'd plan accordingly.

Instead, I would look for WR-90 transitions, which are rated 8 - 12 
GHz and perform as such. Here in the States, such are easy to find, 
but in New Zealand, I suppose they're much more difficult to find and 
acquire. Transfer of Technology issues may apply, I dunno.

SteveH