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\documentclass{beamer}
\hypersetup{pdfpagemode=FullScreen} % makes your presentation go automatically to full screen
\usepackage{textpos}
\usepackage{mathabx}
\usetheme[numbering={true}]{mtt}
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\begin{document}
\title[TH2A-2]{A new method to measure pulsed RF time domain waveforms with a sub-sampling system} 
%\subtitle{subtitle}
\author{T. Reveyrand$^1$ and Z. Popovi\'{c}$^2$} 
\date{\today} 
\institute{ \tiny{$^1$ XLIM - CNRS, UMR 6172, 123 Av. A. Thomas, 87060 Limoges Cedex, France} \\ 
  \vspace{-0.2em}{\tiny tibo@xlim.fr} \\
 $^2$ ECEE, University of Colorado at Boulder, 425 UCB, CO 80309, USA \\ 
  \vspace{-0.2em}{\tiny zoya@colorado.edu} \\ 
   }
\begin{frame}[plain]
  \titlepage
\end{frame}
\begin{frame}{Table of contents}
  \tableofcontents
\end{frame}
%\section*{Introduction} 
\begin{frame}{Introduction} 
  \begin{columns}
   \begin{column}{0.55\paperwidth}
     Designing very high efficiency Power Amplifiers requires transistors level characterizations such as :\\
      \begin{itemize}
        \item Large-signal measurements ;
        \item RF time-domain measurements ;
        \item Pulsed mode for radar applications ;
      \end{itemize}
  \end{column}
  
  \begin{column}{0.40\paperwidth}
  	\vspace{-15pt}
     \begin{figure}
			\includegraphics[height=6.8cm]{fig/intro.pdf}
	\end{figure}
  \end{column}
  \end{columns}
  
\end{frame}
\section{Bench} 
\subsection{Setup} 
\begin{frame}{Large-Signal Measurement Setup} 
       \begin{figure}
			\includegraphics[height=5.5cm]{fig/bench.pdf}
	\end{figure}
\end{frame}
\subsection{Calibration} 
\begin{frame}{Calibration Procedure (CW)} 
  \begin{columns}
   \begin{column}{0.45\paperwidth}
    \begin{itemize}
     \item  SOLT
      \item  Absolute Power
     \item   Absolute Phase
   \end{itemize}
 \vspace{0.5cm}	
\scalebox{0.8}{
$\begin{pmatrix}a1\\b1\\a2\\b2\end{pmatrix}=\left\| K \right\|.e^{j.\phi}.\begin{bmatrix}1&\beta_1&0&0\\\gamma_1&\delta_1&0&0\\0&0&\alpha_2 & \beta_2\\0&0&\gamma_2&\delta_2\end{bmatrix}.\begin{pmatrix}R1\\R2\\R3\\R4\end{pmatrix}$
}
 \end{column}
 
    \begin{column}{0.50\paperwidth}
       \begin{figure}
			\includegraphics[height=5.5cm]{fig/calibration.pdf}
	\end{figure}
   \end{column}
    \end{columns}
\end{frame}
\section{Receivers} 
\begin{frame}{Receivers for CW measurements} 
 \begin{itemize}
        \item NVNA approach : frequency domain
       \begin{figure}
			\includegraphics[height=2cm]{fig/receiver_NVNA.pdf}
	\end{figure}
	
	 \item LSNA approach : subsampling
	 
	        \begin{figure}
			\includegraphics[height=3.2cm]{fig/receiver_LSNA.pdf}
	\end{figure}
 \end{itemize}
\end{frame}
\subsection{Mixer based (NVNA)} 
\begin{frame}{Mixer based pulsed measurements (NVNA)} 
       \begin{figure}
			\includegraphics[height=6.5cm]{fig/NVNA.pdf}
	\end{figure}
	\begin{textblock*}{4cm}[0,0](200pt,-200pt)
	$P_{pulse}=P_{meas}.{\left(\frac{T}{\tau}\right)}^2$
	\end{textblock*}
\end{frame}
\subsection{Sampler based (LSNA)}
\begin{frame}{Sampler based pulsed measurements (LSNA)} 
 $f_{RF}=1.5 GHz$ \hfill  $\tau_{pulse}=10\mu s$\hfill  $T_{IF}=8\mu s$
       \begin{figure}
			\includegraphics[height=2.5cm]{fig/fig1.pdf}
	\end{figure}
	%\pause
       \begin{figure}
			\includegraphics[height=3.5cm]{fig/fig2d.pdf}
	\end{figure}
\end{frame}
\section{Algorithm} 
\begin{frame}{About inner-products}
According to a dictionary
$$\mathcal{D} = {\left\{\psi_k\right\}}_{k\in\Gamma}  $$
$x\left(t\right)$ can be represented by its inner-products coefficients \\
$$\left\langle x,\psi_k\right\rangle = \int_{-\infty}^{+\infty}x\left(t\right).\overline\psi_k\left(t\right).dt$$
If $x\left(t\right)$ is sparse in $\mathcal{D}$ then
$$x\left(t\right)\approx\sum_{k\in\Lambda\subset\Gamma}\left\langle x,\psi_k\right\rangle . \psi_k$$
\end{frame}
\subsection{Frequency Analysis} 
\begin{frame}{What is a Fourier Transform ?}
\begin{columns}
  \begin{column}{58mm}
      \begin{itemize}
        \item $ \mathcal{D}={\left\{\psi_f\left(t\right)=e^{j.2.\pi.f.t}\right\}}$
        \item $X\left(f\right)=\left\langle x,\psi_f\right\rangle$
      \end{itemize}
       \begin{itemize}     
        \item $x\left(t\right)=\int_{-\infty}^{+\infty} X\left(f\right) e^{j.2.\pi.f.t} df$
        \item $X\left(f\right)=\int_{-\infty}^{+\infty} x\left(t\right) e^{-j.2.\pi.f.t} dt$
              \end{itemize}
       \begin{itemize}  
        \item $x\left(t\right)\approx\sum_{k} X\left(k.f_0\right) e^{j.2.\pi.k.f_0.t} $
      \end{itemize}
      \vspace{10pt}
      Standard LSNA uses boxcar window
  \end{column}
  \begin{column}{58mm}
  		Projection basis :
       \begin{figure}
			\includegraphics[height=4.5cm]{fig/fourier.pdf}
	\end{figure}
  \end{column}
\end{columns}
\end{frame}
\subsection{Time-Frequency Analysis} 
\begin{frame}{The Short Time Fourier Transform }
Rectangular STFT is well suited for harmonic analysis
\vspace{10pt}
\begin{columns}
  \begin{column}{58mm}
      \begin{itemize}
        \item $\mathcal{D}=\left\{\psi_{k,\tau}\left(t\right)\right\}$
        \item $\psi_{k,\tau}\left(t\right) = P_k.\psi_k\left(t-\tau\right)$
       \end{itemize}
       \begin{itemize} 
        \item $\psi_k\left(t\right)~=~\Pi\left(f_0.t\right) e^{j.2.\pi.k.f_0.t}$
        \item $ P_k=f_0.e^{j.2.\pi.k.f_0.\tau}$
       \end{itemize}
       \begin{itemize} 
         \item $X\left(k.f_0,\tau\right)=\overline P_k.x\left(t\right)\convolution\overline\psi_k\left(t\right) $ 
               \end{itemize}       
  \end{column}
  \begin{column}{58mm}
    	Projection basis :
       \begin{figure}
			\includegraphics[height=4.5cm]{fig/psi.pdf}
	\end{figure}
  \end{column}
\end{columns}
\begin{center}
\fbox{$ X\left(k.f_0,\tau\right)=\overline P_k.\mathcal{F}^{-1}\left\{ X\left(f\right).\overline\Psi_k\left(f\right) \right\}$}
\end{center}
\end{frame}
\begin{frame}{LSNA software modifications} 
\begin{columns}
  \begin{column}{58mm}
Standard procedure
       \begin{figure}
			\includegraphics[height=3cm]{fig/algo1.pdf}
	\end{figure}
	%\pause
	\vspace{-10pt}
       \begin{figure}
			\includegraphics[height=2.5cm]{fig/fig2d.pdf}
	\end{figure}
	
	  \end{column}
  \begin{column}{58mm}
  New procedure
         \begin{figure}
			\includegraphics[height=6cm]{fig/algo2.pdf}
	\end{figure}
   \end{column}
\end{columns}
  
\end{frame}
\section{Results} 
\begin{frame}{Experimental view of the algorithm} 
 $f_{RF}=1.5 GHz$ \hfill  $\tau_{pulse}=10\mu s$\hfill  $T_{\psi}=8\mu s$\hfill  $k\in\left\{1,2,3,4\right\}$
       \begin{figure}
			\includegraphics[height=6.5cm]{fig/fig3_c.pdf}
	\end{figure}
\end{frame}
\begin{frame}{LSNA pulsed measurements on a PA ($T=100\mu s$)} 
 $f_{RF}=1.5 GHz$ \hfill  $T_{\psi}=8\mu s$ \hfill  $k\in\left\{1,2,3,4\right\}$
       \begin{figure}
			\includegraphics[height=6.5cm]{fig/example.pdf}
	   \end{figure}
	   
	   	\begin{textblock*}{20mm}[0,0](100pt,-185pt)$\tau=10 \mu s$\end{textblock*}
	   	\begin{textblock*}{20mm}[0,0](250pt,-185pt)$\tau=50 \mu s$\end{textblock*}
	   	\begin{textblock*}{20mm}[0,0](100pt,-95pt)$\tau=100 \mu s$\end{textblock*}
	   	\begin{textblock*}{20mm}[0,0](250pt,-95pt)$CW$\end{textblock*}
\end{frame}
\appendix
%\section*{Conclusion}
\begin{frame}{Conclusion}
 \begin{itemize}
        \item Standard LSNA harware can measure pulsed RF
        \item Minimal software modification (FFT procedure)
        \item Compatible with CW and pulsed signals
        \item Adaptive method 
         \begin{itemize}
			\item No trigger
			\item Pulse's width and period ($\tau$, $T$) not required 
         \end{itemize}
        \item Both 'Average' and 'Envelope Transcient' modes availables
 \end{itemize}
 
 Future work :
 \begin{itemize}
        \item Narrow pulses (double aliasing)
        \item Other types of modulation
 \end{itemize} 
\end{frame}
%\begin{frame}[allowframebreaks]{References}
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\end{document}