¿Cómo puedo ajustar estos sorteos en la misma línea horizontal?

Question

Como son los circuitos:

Intenté usarlo \begin{circuitikz}[american voltages, baseline=(current bounding box.base)]en lugar de \begin{circuitikz}[american voltages, baseline=(current bounding box.center)]pero \leftrightarrow permaneció en una mala posición.

Código completo:

\documentclass[11pt]{article}

\usepackage{circuitikz}
\usepackage{tikz}                           % for flowcharts

\begin{center}
        \begin{circuitikz}[american voltages, baseline=(current bounding box.center)]
        \ctikzset { label/align = straight }
        \draw (0,0) 
        to[sV_<=$\hat{V_S}$] (0,-2)
        to[short, -o] (3,-2)
        (0,0) to [fullgeneric, l=$\hat{Z_S}$, -o] (3,0)
        {[anchor=west] (3,0) node {a} [anchor=west] (3,-2) node{b}};
        \end{circuitikz}
        $\hspace{0.25in} \displaystyle \Leftrightarrow \hspace{0.25in}$
        \begin{circuitikz}[american voltages, baseline=(current bounding box.center)]
        \ctikzset { label/align = straight }
        \draw (0,0) 
        to[sI=$\hat{I_S}$] (0,-2)
        to[short, -o] (3,-2)
        (0,0) to[short, -*] (2,0)
        to [fullgeneric, l=$\hat{Z_S}$, -*] (2,-2)
        (2,0) to [short, -o] (3,0)
        {[anchor=west] (3,0) node {a} [anchor=west] (3,-2) node{b}};
        \end{circuitikz}
        \end{center}
\end{document}

Answer 1

Debido a que los circuitos tienen diferentes alturas, la forma más sencilla parece ser la corrección manual de sus posiciones, por ejemplo:

\documentclass[11pt]{article}

\usepackage{circuitikz}
\usepackage{tikz}                           % for flowcharts'

\begin{document}

%\begin{center}
\begin{tabular}{ccc}
\begin{tabular}{c}
        \begin{circuitikz}[american voltages, baseline=(current bounding box.center)]
       % \ctikzset { label/align = straight }
        \draw (0,0) 
        to[sV_<=$\hat{V_S}$] (0,-2)
        to[short, -o] (3,-2)
        (0,0) to [fullgeneric, l=$\hat{Z_S}$, -o] (3,0)
        {[anchor=west] (3,0) node {a} [anchor=west] (3,-2) node{b}};
        \end{circuitikz}
\end{tabular}
&
\begin{tabular}{c}
\\[5mm]
        $\hspace{0.25in} \displaystyle \Leftrightarrow \hspace{0.25in}$
\end{tabular}
&
\begin{tabular}{c}
\\[5mm]
        \begin{circuitikz}[american voltages, baseline=(current bounding box.center)]
      %  \ctikzset { label/align = straight }
        \draw (0,0) 
        to[sI=$\hat{I_S}$] (0,-2)
        to[short, -o] (3,-2)
        (0,0) to[short, -*] (2,0)
        to [fullgeneric, l=$\hat{Z_S}$, -*] (2,-2)
        (2,0) to [short, -o] (3,0)
        {[anchor=west] (3,0) node {a} [anchor=west] (3,-2) node{b}};
        \end{circuitikz}
 %       \end{center}
\end{tabular}
\end{tabular}
\end{document}