Comments

  • IEEE MTT-S and Microwaves101
    I totally forgot about the forum (message board) being wiped clean. It never really came back after that, people moved on. Here we are, the proverbial tree falling in the forest.

    Thanks for your thoughts!

    Steve
  • OMTs
    That is a great question! I took a look around, some designs just show a three-port box with labels...

    Maybe a picture like this?

    https://en.wikipedia.org/wiki/Orthomode_transducer#/media/File:Orthomode-transducer_01.jpg

    Sorry I am not a huge help, I'll try to ask an antenna person.

    Steve
  • Reactive power combiners
    Thanks

    there will likely be some routing between the combiner and the amplifiers, so I consider the phase angle of the failure unknown, and possibly a strong function of frequency. The failure could be a short circuit somewhere back inside the amplifier, or a blown wirebond, or almost anything. For sure, adding the isolation resistor will help the remaining amplifiers see a decent match, with the caveat that the resistor does not blow up...

    I will take a look at the reflection coefficients that are seen by constituent amplifiers in a combiner, when the amplifiers have random phase and amplitude errors, and see what that tells me..
  • wire and coax impedance
    Not sure I understand where this comes from

    Z= Zo x sqrt(mu_r/epsilon_r)

    But I'll try to give it some more thought!

    Thanks
    Steve
  • Network analyzer repair
    Thanks! Someone should be getting in touch...
  • SiC heat spreaders
    You know, I have been looking for an excuse to visit them... I'll try to get over there and ask. Need to be sensitive about anything proprietary of course. Thanks for asking!
  • Network analyzer repair
    Thanks! That is a very active message board, I will peruse it. But I don't want to take on a project like this, it might end up in forgotten pieces as my attention span is pretty short these days. I wonder if Shariar at Signal Path (on Youtube) would do contract work or knows someone that does...

    Steve
  • June's newsletter examples using scikit-rf
    Thanks, I will add a link to that info. I know who to call when I need help on de-embedding!

    Great news on the scikit-RF shirt my old one is in tatters and stained from doing an oil change. Will order a new one.

    Steve
  • Surface treatment on aluminium
    Is this for waveguide?
  • SiC heat spreaders
    Turns out MSE Supplies in Tucson can thin SiC wafers if anyone else is interested

    Thanks
  • SSPA power combiner
    My friend
    You have pointed out the weak part of Wilkinsons in SSPAs.... the resistor is going to blow up!
    Steve
  • SiC heat spreaders
    Still have yet to find a source for this...

    Steve
  • History of PIM (Passive Inter-Modulation products)
    All of the pages on Microwaves101 on PIM were contributed by Jack Kouzoujian, maybe 20 years ago. He was (is?) the head of Matrix Test Equipment. If you can find him, he could be a lot of help.

    http://www.matrixtest.com/


    Steve
  • Near Field Microwave Measurements
    isn't this something you can buy from MilliBox? I am by no means an antenna guy...

    https://millibox.org/anechoic-chamber/

    Steve
  • wire and coax impedance
    At some point I would like to capture the ipedance formula that takes into account mu... let me know where there is a good explanation of that.

    The microwave office TXLine calculator does show some effect on Z0 when resistance increased, but not enough to explain a 10% shift.

    Steve
  • SiC heat spreaders
    It is a very hard material to grind.... that is why they make sandpaper out of it! someone told me about a shop that can hopefully do this::

    https://arcnano.com/

    Thanks again
    Steve
  • Miller MMICs
    WIN semi would also be my guess. I wonder how many other fabless companies use them...

    Thanks!
  • DC biasing connection on MW LNAs
    There might be some type of header that fits over the drain supply pin, but that would not work on the ground lug. Honestly, I like your idea, especially since you never have to worry about a clip-leab falling off!

    Steve
  • Connectors suitable for a TRL calibration (microstrip)
    It does seem weird that there are 2.92 to 3.5mm adapters available... how accurate do you need a calibration? if you don't work for NIST maybe you can ignore a slight discontinuity.

    I would like to see the data sheet on the 2.92 mm connector with dielectric.... Thanks!

    Keep in touch!
    Steve
  • AWR DE(Microwave office)
    I'm not sure I have this, but I'll look at some old MWO files. If you have the calculation in Excel or just equations can you provide them?

    Steve

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