veriloga balun model
If a signal adds to the single-end of a balun, the balanced-outputs get two inverse signals; if two balanced signals add to the balanced-outputs, the single-end get a signal which is the difference of the inputs.
While I have a question that if I add a signal to one of the balanced-end, while the other balanced-end and the single-end floating(or add a 50 ohms load), can I get a inverse signal at the other balanced-end?
I simulated the balun model in rfLib of c@dence, when i do so, the other balance-end get nothing, but i wonder that are all the actual baluns do not coupling their balanced-out?
Thanks.
If you put a signal to one of the balanced-end and the other balance-end is loaded (50 ohms), you will get 90 degrees shift of the signal to the un-balanced port.
If the other balanced-end is floating, you will get 180 degrees shift to the un-balanced port.
Thanks for reply.
Do you mean an actual balun has this performance?
But when I simulate the "Balun" from rfLib by spectre, the other un-balance end has no signal at all. Where can I get a balun model with the characteristic you said? Or should I write it by myself?
RF simulators like MWO, ADS, Eagleware, Ansoft, have different types of balun models (microstrip, ferrite, coaxial, etc). Or you can build your own.
I have only c@dence. How to build a models for balun? I modified the veriloga file of the balun in rfLib. But it doesn't work correctly. Could you pls give me some advices on how to build it? Or tell me where can I find the documents about build a model?
Thanks.[/b]
You can design a lumped element balun in Cadence.
http://www.odyseus.nildram.co.uk/RFM...n%20Design.pdf
or using AppCAD from Agilent that have option: Lumped Element Balun Design
http://www.hp.woodshot.com/
http://www.poynting.co.za/tech_training/tut_balun.shtml