Firstly - Fantastic Piece of Kit - thank you to the community that brough us the NanoVNA!

So I am using this to characterise an PCB based antenna. Using the NanoVNA I have taking the following measurements (see screen shots).

I want to build a PI matching filter to match this antenna to an F=868mHz, impedance of 50R..  The Nano for this Freq is giving me an impedance of Z=13.47-j39

All of the tutorials that do this, using a smith chart read the values from the smith chart and use that to plot the Zo to correct it, and then use this calculate the L and C values, but I don't see a way of doing this with the NanoVNA.

How do I do this with a NanoVNA plus?  Whats the math I need to apply or can the Nano do this for me?

thanks

Dave

No, Nano won't do the math. I'd recommend you to have a look at SimSmith software, great learning tool to understand Smith charts and impedance matching.

Another good one that is free for up to 5 elements.
http://www.fritz.dellsperger.net/smith.html

Hello Dave,

I use the progam "smith" from J.Dellsperger to solve such problems. Look
at the picture.

73, Guenter, DK5DN

Am 02.01.2022 um 22:07 schrieb dave@conficioltd.com:

> Firstly - Fantastic Piece of Kit - thank you to the community that
> brough us the NanoVNA!
>
> So I am using this to characterise an PCB based antenna. Using the
> NanoVNA I have taking the following measurements (see screen shots).
>
> I want to build a PI matching filter to match this antenna to an
> F=868mHz, impedance of 50R..  The Nano for this Freq is giving me an
> impedance of Z=13.47-j39
>
> All of the tutorials that do this, using a smith chart read the values
> from the smith chart and use that to plot the Zo to correct it, and
> then use this calculate the L and C values, but I don't see a way of
> doing this with the NanoVNA.
>
> How do I do this with a NanoVNA plus?  Whats the math I need to apply
> or can the Nano do this for me?
>
> thanks
>
> Dave
>

SimSmith includes various matching topologies built into the various
applications within the program. It will do the math for you. Download
and install SimSmith from the following URL:

http://www.ae6ty.com/smith_charts.html

An excellent tutorial has been written by WØQE and can be accessed at:

https://www.w0qe.com/SimSmith.html

Dave - WØLEV

On Mon, Jan 3, 2022 at 4:29 AM <dave@conficioltd.com> wrote:

> Firstly - Fantastic Piece of Kit - thank you to the community that brough
> us the NanoVNA!
>
> So I am using this to characterise an PCB based antenna. Using the NanoVNA
> I have taking the following measurements (see screen shots).
>
> I want to build a PI matching filter to match this antenna to an F=868mHz,
> impedance of 50R.. The Nano for this Freq is giving me an impedance of
> Z=13.47-j39
>
> All of the tutorials that do this, using a smith chart read the values
> from the smith chart and use that to plot the Zo to correct it, and then
> use this calculate the L and C values, but I don't see a way of doing this
> with the NanoVNA.
>
> How do I do this with a NanoVNA plus? Whats the math I need to apply or
> can the Nano do this for me?
>
> thanks
>
> Dave
>
>
>

--
*Dave - WØLEV*
*Just Let Darwin Work*

On Mon, Jan 3, 2022 at 01:26 AM, Wojtek SP9WPN wrote:

>
> No, Nano won't do the math. I'd recommend you to have a look at SimSmith
> software, great learning tool to understand Smith charts and impedance
> matching.

In my fw for nano exist Measure->L/C MATH (on old fw in Marker->Measure->L/C MATH)
in this mode Nano calculate up to 4 solution how made 50 Om from measured data at current marker frequency

Pasan is an nice start to learn about matching with smith chart. It's easy to learn and how to use...
Free downlaod here:
http://www.science4all.nl/?Electronics___Pasan

Karl

PS. As DiSlord says, matching calculations are built into his firmware...

Thanks Schweppe ..  thats looks really interesting, I'll have a look at this now..

On Mon, Jan 3, 2022 at 09:26 AM, Wojtek SP9WPN wrote:

>
> SimSmith software

Thanks Wojtek - just working my way through this

Thanks for replay Dave - taking a look now and getting my brain warmed up!