Waveguide standard transition
Waveguide standard transition
(OP)
I look for explanation where to find construction tips ( maybe some cross section photos) for waveguide probe
http://www.alibaba.com/product-detail/Antenna-Prob...
or similar or where to find some physical bacground for this probe,
I found also that it is standardised part , Which standard ?.
Regards
http://www.alibaba.com/product-detail/Antenna-Prob...
or similar or where to find some physical bacground for this probe,
I found also that it is standardised part , Which standard ?.
Regards
RE: Waveguide standard transition
RE: Waveguide standard transition
This is my Idea how this works, but I need some more explanations. I am not so familliar with TE and TM and waveguides and I have no skills how to construct and aliggn (calibrate) this probe. It shall be fine that someone explain more or show where to find explicit knowladge about this probe.
Best regards
Andrej
RE: Waveguide standard transition
Is that your question? How to adjust the screws for lowest reflection?
RE: Waveguide standard transition
RE: Waveguide standard transition
I wonder if the intermediate section (gold color section) is a waveguide or perhaps a section of transmission line. If it were waveguide, then it would need to contain launch and output probes inside at each end; and that seems very unlikely given the size. I wonder if it might be a section of coaxial transmission line.
The screws appear to be a tuner, and that can still be true with a section of transmission line. Adjusting procedure is usually "Adjust for best match" and I don't recall ever seeing any step-by-step. More a simple trial and error using suitable test equipment. I don't think it's difficult. There will be some interaction, but it's not overly difficult to tweak them in sequence until a good match is achieved.
RE: Waveguide standard transition
Any ideas.
So thank you
Best Regards
Andrej
RE: Waveguide standard transition
Plus, I don't think that the gold section is big (wide) enough to contain 2.4 GHz waves (microwave oven frequency) as a waveguide. It would have to be about four times wider than X-band WR90, and it's clearly not.
The only procedure I've ever seen was as simple as "Adjust for best match".
RE: Waveguide standard transition
I still think that between N connector and antenna is a waveguide, It is multiscrew tuner .... I will make an citation (Engineers Handbook of industrial Microwave heatin - R. Merdith)... "Each screw provides a variable, capacitive susceptance whose amplitude is a function of its insertion into waveguide and the diameter of the screw.If four such screws are considered, spaced apart by lambda/8, then , for small reflections, the screws can be seen to give, at a reference plane located at the first screw an admitance adjustment of -+ jb for screws 1 and 3 and conductance adjustment -+dr for screws 2 and 4. Within the adjustment range it is therefore possible to generate reflection of any amplitude and phase simply by setting the screws for minimum net reflected power from load/tuner combination"
Ok ... I also found how to calculate this part, It is an old NIST document ..., But about lounch and output probes or maybe loops I haven t find nothing on net .
About adjustment to best mach is still a question, I do not know the impedance I have to match, It is in some connection with Rieke diagram which represent magnetron characteristics where a mismatch ( forom 50 ohm) conditions are evident.
Funny. Magnetrons, measurements etc. are an old technology from WW2, There is a lot of informations ( MIT courses), But when I want to find an answer for this specific microwave part for measurements ( I found iti is standardised part in an Japan standard ??) there is "blind spot" about this on Web pages.
Have a nice weekend ..
Best regards
Andrej