rflib balun

Dear all~~!
Thank in advance.

Now , I need Balun component for RF spectre simulation.

I found two balun, rfLib/balun and analogLib/ideal_balun.

Two baluns have different characteristics.

In rfLib/balun,
In attached file, when differential input is 2Vpp, single output decrease 1.414Vpp.
I don't understand why the single output decrease.

In analogLib/ideal_balun,(the same condition in attatched file, ideal_balun doesn't set the balanced ouput impedance, single input inpedace)
when differential input is 2Vpp, single output is 2Vpp!

What is correct?

~!

The balun in rflib works as a power splitter.
You can also refer this file (search "A test bench for differential circuits") to see how does the ideal_balun in analogLib works.