I would like to know how the two circuits are equivalent.

[zxcv2201]

I am reading the following paper, and it is difficult to understand that the circuit in the picture is an equivalent circuit. Is there anyone who can tell me how the two circuits are the same?

"A fully differential ultra-compact broadband transformer based quadrature generation scheme"

 

[FvM]

Your circuit schematics have no terminals or sources. Also the transformer lacks any parameters (ideal or has Lh + Ls, n1:n2). Impossible to tell if and which regard they are equivalent.

 

[KlausST]

Hi,

In addition to FvM:
Let's say you have an R and a C in series.
You may build/calculate an equvalent circuit where R and C are in parallel....but only for one dedicated frequency.

Let's say a 1k + 100nF in series may be eqivalent to 1.5k || 68nF but only at a dedicated frequency.
(Just as example, I did not take the effort to do true calculations)

But for the eqivalent usually neither C nor R will keep it's value.

Klaus

 

[danadakk]

Do you have a link to the paper ?

Regards, Dana.

 

[zxcv2201]

It seems that I am replying incorrectly because I am not familiar with how to use the page. Thanks for all replies, here is the link:

A fully differential ultra-compact broadband transformer based quadrature generation scheme

This paper presents an ultra-compact transformer-based quadrature generation scheme, which converts a differential input signal to fully differential quadrature outputs with low passive loss, broad bandwidth, and robustness against process variations. A new layout strategy is proposed to...

ieeexplore.ieee.org

 

[KlausST]

It seems that I am replying incorrectly because I am not familiar with how to use the page. Thanks for all replies, here is the link:

just use the "preview" button (top right of the editor window) to check your post.

Klaus

 

[mtwieg]

In the original paper, the circuits are three-port networks, with the resistors representing ports. With that in mind, it's fairly straightforward to see how they are equivalent if the transformer has no leakage (k=1), a 1:1 turns ratio, and magnetizing inductance equal to L in the first figure.