Wilkinson.

@uploadJ yes, Wilkinson

Me too, this is serious witchdoctor stuff.

@@monteceitomoocher not there yet either, I still got to write my thesis, haha.

I think I see 90 degree hybrids in there; That's what gives the extra port labeled "ISO" for Isolation ...

The tool you want is Spectrum Analyzer; the 8-bit digitization/quantization of an O-scope is inadequate to see harmonics down 40 dB and more.

Conventional scopes barely have the sample rate good enough to measure such high frequencies unless you have incredibly deep pockets :-). Oftentimes with RF design, you test every stage on a seperate PCB with seperate connectors so you have good coupling. Then you use a network analyser to tune it, do impedance matching, biasing etc. and characterize it. It sweeps an RF signal at the input, then it looks at the amplitude (if your have a fancy analyzer also phase) at both the output (as transmission) and input (as reflection). You can even do this in reverse putting a signal into the output and look what comes through at the input. He did a great video about scattering matrices not too long ago that explains this in great detail. I'm sure he'll demonstrate this in the coming videos! But for RF, you're not interested in the shape of the waveform, mostly the harmonics and the power. When everything works like expected, you jam everything together on a large circuitboard. I do have to say, the more seperate RF parts on such a board, the horrificness of doing all the matching grows exponentially, but I guess the charme of becoming an RF engineer is the hands-on-ness of the design process and large variation within the same series of components hahahaha.

@@BeesKneesBenjamin re: "Oftentimes with RF design, you test every stage on a seperate PCB with seperate connectors" With the P4 (Project 4 WiMAX) at Cisco (was Navini) the entire unit was simply proto-typed; debug/inspection of various stages for design troubleshooting employed in-circuit use (splice into the RF path) of Spec AN and Vector Net Ana but we did not, b/c of the density of the 8-ch phased array first do individual stages eval ... now, evaluation boards for various stages/components/system chips are available from the manufacturer so evaluation is made at the device level. Using quality FR4 or Nelco RF-capable board material takes out the guesswork or removes the need to evaluate every new production model since repeatability is achieved with pre-preg multi-layer board stackups.

@@uploadJ I think in this case then our differences design processes are more likely branche-related. We exclusively do measurement equipment for scientific research. The selection of chips and modules has gotten quite large but we often still need to do a lot of discrete designs where we need really high stability or a very specific function at the cost of repeatability. Hence we still do a lot of tuning by hand and extensive calibration processes in order to keep variation between units incredibly low. Ofcourse we also use computer aided design every now and then and in this branche manufacturing cost is only a fraction of the price of the entire unit so we use excellent PCB materials. But at the end of the design process we often end up with PCBs we can get somewhat reliably manufactured, but we will always need a couple adjustments here and there. For quite elaborate prototypes, we also tend to incorporate extra connectors which can be connected by replacing a capacitor or a 0R resistor somewhere. Once it's characterised the connectors are taken off and it's mounted in a case. Most measurements are taken with a VNA or spectrum analyser or we specifically design testsets for specific calibration steps. This is obviously unsuitable for mass-manufacture, but in our field it doesn't happen often we sell two identical devices :-)

@@BeesKneesBenjamin re: "The selection of chips and modules " For our project, we used a TI made demod chip that took I and Q LO and provided I and Q baseband for digitizing ... anymore, in the telecom/wireless biz it is incorporating a chip vendor's block' function device and less discrete design with transistors, diodes, Rs and Cs ... although power amp design still calls for discrete design skills. Modelling may be the first step, but it takes skill to realize when vendor parts aren't conforming or deviate from nominal specs; RF parts/components being the worst once into production.

Because it's at least 20 years old obsolete

@@StbLexBoussole I guess I didn't consider that possibility lol

;~) and never be able to acknowledge a packet

@@NickNorton OK Maybe I might need two of them. One might look a little odd strapped to my Thinkpad though, and somewhat limit the battery life. On the plus side however, I cold probably work from home anywhere within twenty miles of the router, but then again I would have to keep a watchful eye out for the WiFi police.

www.digikey.com/en/blog/the-reasons-for-50-ohm-and-75-ohm-transmission-lines#:~:text=The%2050%20%CE%A9%20value%20is,%CE%A9%20is%20a%20better%20choice.

@@IMSAIGuy Perfect! Thank you 👌

watch parts 2 3 4