Hittite's switch s-parametars problem

[goxy]

In my project I'm using serial configuration of switches like in posted file.
Input parametars are very bad after 4 of them.
I'm find cure in attenuator to improve perfomance but I'm not sure is this ok.
In S-parametars file: https://www.hittite.com/s_parameter_download.cfm?file=HMC347LP3.zip
is wroted "Data includes two SRI SMA connectors".
I think this connectors affect on sistem because 4 switches include 8 connectors.
What to do :roll:

 

[flatulent]

deimbedded

The s parameter files say deembedded which would make you think that they eliminated the effects of the connectors on the test board. On the other hand the s parameter traces wind around the center of the smith chart many times which looks like transmission line effects. In any case notice that the SWR is always worse than 1.5. Stacking many of these in tandem will produce a huge loss of signal.

Try contacting Hittite and ask them. They are a very friendly company and you will probably get to talk to the person who took the measurements.

I always design with their parts first choice because the data sheets are correct and not optimistic.

 

[goxy]

Thanks flatulent!

Application engineer will contant me.

What do you think about soldering this 3x3mm package?

 

[flatulent]

soldering

I suggest for all surface mount work using a Metcal brand soldering iron. The newer 50W model is preferred because of the wider selection of tips. If you are not at a wealthy company, the 35W versions can be bought used at ebay type sites. Go to the Metcal web page and download and read their application notes on tips to use and how to apply them to the chips.

I also suggest a microscope designed for surface mount work. They have variable magnification in the 3x-10x range. They also have heavy bases and long horizontal arms to position the optics over the lab bench with no obstructions for positioning the PC card.

Get one with a light source that is a complete circle around the lens. This will illuminate the work from all angles and your iron and tweezers will not cast shadows.

Do not economize on the tweezers. Cheap ones will not hold the chips well and frequently fling them across the room.

 

[goxy]

I'm find right tool for this package-Metcal Hot Air Pencil

Can you give me some advice about PCB, I'm scare because copper trace oxidizes and so high frequency(11Ghz).
What about Rogers Duroids and some protection(gold or silver) or some other layout type?

 

[flatulent]

board material

At these frequencies the Duroid type material is much better than FR4. They should be able to tell you about the long term losses from oxidation. Remember that on microstrip, the currents are mostly on the side of the copper that faces each other across the dielectric. These are sealed from the atmosphere and should not oxidize.

 

[goxy]

Ok, Regards!