%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Own Simulations}
\label{sec:Own Simulation}

\begin{frame}
	\frametitle{Design Steps}

	\begin{enumerate}
		\item Determination of operating point of individual stages
		      \begin{itemize}
			      \item SQuad
			      \item TIA
			      \item Buffer
		      \end{itemize}
		\item Integration
		      \begin{itemize}
			      \item SQuad \& TIA
			      \item SQuad, TIA \& Buffer
		      \end{itemize}
		\item Matching of input and output
		\item Replacement of remaining DC blocks/feeds in bias circuitry
		\item Final optimization
	\end{enumerate}
\end{frame}

\begin{frame}
	\frametitle{Operating Point: Switching Quad}

	\begin{minipage}{0.5\textwidth}
		\begin{itemize}
			\item Operation
			      \begin{itemize}
				      \item Responsible for actual mixing
				      \item Multiplication of RF-signal with square wave $\rightarrow$ generation of mixing products at IF-frequency and harmonics
			      \end{itemize}
		\end{itemize}
		\bigskip
		\begin{itemize}
			\item Determination of operating point
			      \begin{itemize}
				      \item Exact value of $V_\text{CE}$ not crucial
				      \item $V_\text{BE}$: Examination of $s_\text{21}$
				            of Large-signal s-parameter simulation and noise figure (analogous to \citereference{Mai+21})
				      \item [TODO] (Simulate noise figure or remove text)
			      \end{itemize}
		\end{itemize}
	\end{minipage}%
	\begin{minipage}{0.5\textwidth}
		\centering
		\begin{figure}[H]
			\vspace*{-5mm}
			\hspace*{15mm}%
			\includegraphics[width=0.83\textwidth]{res/simulation/SQuad_OP_01.pdf}

			\vspace*{-18mm}
			\hspace*{-55mm}%
			\includegraphics[width=0.4\textwidth]{res/simulation/SQuad_OP_02.pdf}
		\end{figure}
	\end{minipage}

	\vspace{4mm}
	\addreference{Mai+21}{T. Maiwald et al., ``A Broadband Zero-IF Down-Conversion Mixer in 130 nm SiGe BiCMOS for Beyond 5G Communication Systems in D-Band'', in \emph{IEEE Transactions on Circuits and Systems II: Express Briefs}, vol. 68, no. 7, pp. 2277-2281, July 2021}
\end{frame}

\begin{frame}
	\frametitle{Operating Point: Transimpedance Amplifier}

	\begin{minipage}{0.5\textwidth}
		\begin{itemize}
			\item Operation
			      \begin{itemize}
				      \item Conversion of switched current to voltage, amplification
				      \item Modified Cherry-Hooper topology: decoupling of bandwidth and gain, modification for greater dynamic range
			      \end{itemize}
		\end{itemize}
		\bigskip
		\begin{itemize}
			\item Determination of operating point
			      \begin{itemize}
				      \item Exact value of supply voltage not crucial
				      \item S-parameter simulation: Examination of maximum available gain ($\mathit{MAG}$) and minimum noise figure ($\mathit{NF}_\text{min}$)
			      \end{itemize}
		\end{itemize}
	\end{minipage}%
	\begin{minipage}{0.5\textwidth}
		\vspace*{-6mm}

		\begin{figure}[H]
			\centering
			\hspace*{-8mm}
			\includegraphics[width=0.83\textwidth]{res/simulation/TIA_OP_01.pdf}

			\vspace*{-20mm}
			\hspace*{58mm}%
			\includegraphics[width=0.33\textwidth]{res/simulation/TIA_OP_02.pdf}
		\end{figure}
	\end{minipage}
\end{frame}

\begin{frame}
	\frametitle{Operating Point: Buffer}

	\begin{minipage}{0.45\textwidth}
		\begin{itemize}
			\item Operation
			      \begin{itemize}
				      \item Amplification of signal
				      \item Comprises three stages: two differential amplifiers and an emitter follower
			      \end{itemize}
		\end{itemize}
		\bigskip
		\begin{itemize}
			\item Determination of operating point
			      \begin{itemize}
				      \item Exact value of supply voltage not crucial at this point
				      \item S-parameter simulation: Examination of $\mathit{MAG}$ and $\mathit{NF}_\text{min}$
				      \item \textbf{Note}: Adjustment with respect to linearity at the very end
				      \item [TODO] Switch figure with correct one (add peaking inductance)
			      \end{itemize}
		\end{itemize}
	\end{minipage}%
	\begin{minipage}{0.57\textwidth}
		\vspace*{-5mm}
		\begin{figure}[H]
			\hspace*{2mm}%
			\includegraphics[width=1\textwidth]{res/simulation/Buffer.pdf}
		\end{figure}
	\end{minipage}
\end{frame}

\begin{frame}
	\frametitle{Integration: SQuad \& TIA}

	\begin{minipage}{0.45\textwidth}
		\begin{itemize}
			\item DC coupling $\rightarrow$ Redesign of bias circuitry
			\item Supply voltage fixed to $\SI{2.5}{\volt}$ to not exceed breakdown voltage of transistors
			\item Examination using Harmonic-Balance simulation:
			      \begin{itemize}
				      \item Conversion gain
				      \item $\SI{1}{dB}$ compression point ($P_{\SI{1}{dB}}$)
				      \item[TODO] Noise figure
			      \end{itemize}
		\end{itemize}
	\end{minipage}%
	\begin{minipage}{0.6\textwidth}
		\vspace*{-38mm}
		\begin{figure}[H]
			\includegraphics[width=0.67\textwidth]{res/simulation/INT_SQuad_TIA_01.pdf}

			\vspace*{-50mm}
			\hspace{-70mm}%
			\includegraphics[width=0.28\textwidth]{res/simulation/INT_SQuad_TIA_02.pdf}

			\vspace*{-20mm}
			\hspace{60mm}%
			\includegraphics[width=0.22\textwidth]{res/simulation/INT_SQuad_TIA_03.pdf}
		\end{figure}
	\end{minipage}
\end{frame}

\begin{frame}
	\frametitle{Integration: SQuad, TIA \& Buffer}

	\begin{itemize}
		\item AC coupling $\rightarrow$ No redesign of bias circuitry required
	\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{Further Optimization: \ldots}
\end{frame}

%\begin{frame}
%	\frametitle{Simulation Setup}
%
%    \begin{figure}[H]
%        \centering
%
%        \includegraphics[width=0.6\textwidth]{res/simulation/schematic.pdf} 
%    \end{figure}
%
%	\begin{itemize}
%		\item [TODO] Simulation schematics
%		\item [TODO] Differences to schematic from paper (if any)
%	\end{itemize}
%\end{frame}
%
%\begin{frame}
%	\frametitle{Design Steps}
%
%	\begin{itemize}
%		\item [TODO] Idea: approach from lecture: first worry about actual circuit, biasing later
%		\item [TODO] Choice of transistors
%		\item [TODO] Choice of operating points
%		\item [TODO] Rest of schematic details (?)
%	\end{itemize}
%\end{frame}
%
%\begin{frame}
%	\frametitle{Simulation Results}
%
%	\begin{itemize}
%		\item [TODO] Simulation results
%		\item [TODO] Intuitive explanation of results
%	\end{itemize}
%\end{frame}
%
%\begin{frame}
%    \frametitle{Comparison with Standard Topology}
%
%    \begin{itemize}
%		\item [TODO] (Remove if not applicable)
%        \item [TODO] Comparison of pros and cons of each topology
%        \item [TODO] Comparison of simulation results
%    \end{itemize}
%\end{frame}
