RF parts in PADS Layout

[skywalker]

drc pads layout

Hi,
does someone know how to create and manage RF elements in PA DS La y out and Lo gic ?

RF elements for frequency >1Ghz
Any reply are welcome, Skywalker.

 

[Bouli]

What do you mean "RF elements"?? Is it for example microstrip T-junction?

 

[skywalker]

Hi Bouli,
yes microstrip, T junctions, and other.

For example a microstrip is one piece of copper. But they have two points or pads, for input and output.

The system, generate an insulating error, because the two pads are shorted from copper area of microstrip.

Can some one have any idea ? Skywalker.

 

[Bouli]

As I know you have two ways to do it.
fist - draw the polygon and associate it to the proper net
second - buy RF-kit, which is targeted to do RF PCB

 

[skywalker]

Hi Bouli,
please how to draw a poligon and associate a net ? In P A D S L a y o u t, only a electrical element can be associate to a net, but microstrip have two points or pad, and one is shorted from the electrical area connected to other.

Other R F elements have the same electrical area but 3 or moore pad. How to create a correct d e c al in L a y o u t, but without creating drc errors ?

Please let me know. R F k i t , can you have it ?

Best, Skywalker.

 

[Bouli]

In PCB draw the polygon, click right mouse button, then select "select shape", select the polygon you drew before by 2 mause click (or right click and properities). Then you will see the window with names of all nets in your PCB (eg. $$$123874), chose the correct one, and then there will be no DRC errors eny more.

 

[skywalker]

Hi Bouli.

Your info are right, for normally use of a copper area.

But a specific element with Y or T junction, wich mode to draw it ?
Because the copper poligon are 1, but pad used in schematic are 3 ?
Another question, this need to create a part with decal not only a piece off copper.

However your reply's are appreciate, Skywalker.

 

[skywalker]

Bouli, you know or have a mentioned R F kit ? Work it well ?

Please let me know, Skywalker.

 

[Bouli]

No I didn't work with RF kit, but I know it exist.
I other hand I don't know any better way to do RF parts in powerPCb than polygon of copper.

 

[skywalker]

Hello, Bouli

i agree with you, at the moment we use a copper areas for RF.

Best, skywalker.

 

[Bouli]

In this week I'm suposed to get free demo versions of RF kit to try it. I will let you know how it works.

 

[Bouli]

Hallo
I have RF kit demo version and I can say few words about it. You can also check this site: **broken link removed** unfortunately it is finnish lang.
RF-kit is an independent small software, which can create PADSlogic and PADSpcb library components. PCB components are just adequate polygons with proper dimensions and ports saved as component in PCB library with long numerical name. Every microstrip component (even the same microstrip line) has another PCB decal with uniqe name. And thats all.
Summary: If you work with RF-kit you have to control 3 programs simultaneusly (power logic, power pcb, rf-kit). So it may couse some problems in the beginning. Other problem is that you realy never know if models in your symulator software look like parts created with RFkit. (for ex. mittered bend, or spiral inuctor). In my opinion it is not complex solution for RF PCB desing, but I haven't seen anything better.
Do you want to know more?
PS. I don't thing it is worth its price.

 

[skywalker]

Hello Bouli,
your reply are good. I agree with you, for a lot of arguments. The price are too high, and this demo not work properly. Another problem, not work with a R F simulator.

But reading your report and R F K i t documentation, i make idea to create and manage R F p a r t in L a y o u t.

The d e c a l need two shapes, one of copper on doc layer, and same shape but keep out area and pins in electrical layer used. In this mode the copper (added only in cam out) not short pins and keep out, enable use drc. Is not simple, but work. And is possible to connect this parts in electrical layer.

Let me know what do you think, best Skywalker.

 

[trigger74]

For me, I will ignore the prompt of errors and just draw a polygon as microstrip line

 

[Bouli]

You can associate polygons to the proper nets, set rules, and there will be no more DRC errors, but in that case you won't have documentation of RF pats in PLogic.

 

[g579]

Hi skywalker,

From where you get the RFKit documentation ?
And please describe a little more detailed of component creation.
If it is too long for the forum, please PM me.
Thanks
g579

 

[skywalker]

Hi,
If you want ignore drc netlist parts bom in L a y o ut and L ogi c ecc. no problem, you can work and rework in this mode.
But if management of libs parts nets bom ecc. in pcb and schematic are need, the situation are different. I agree with Bouli.

g579, if you read in the R F kit site, you can read that the soft create a copper and keep out area. This is the key.

For example an Y element, p a rt in pcb are created with 3 element:
1- Y copper on doc layer
2- Y keep out on elec layer
3- n.3 pins in elec layer

The elec layer are controlled by a keep out area, in this mode if any intersect keep out a drc err mark it. The copper area are on doc layer not short pins. The pins are connected with routes in elec layer, in this mode netlist are normally used.

For a schematic, no problem you can create symbol as you wish, Skywalker.

 

[skywalker]

Hi,

g579 the info are detailed for you ? Please let me know.

I think the best way is to, interface R F simulator with Lay*out, for example a specific export for a pcb.
The most important simulators have a module to link with Lay out, but R F designer's, don't know how to use or don't spend time and money for this !

Skywalker

 

[g579]

Hi skywalker,

Thanks for your info. I am looking into it a little deeper than I thought I will. I do not have too much experience in P*A*D*S, so I should think the info you gave over.
I'll come back to you a little later.
Thanks.
g579

 

[pcbman]

Hi,

I know another RF tool : LIBedit RF. You can see it at :
**broken link removed**

pcbman