\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{sams sub}
\pdfinfo{
  /Title (communication-in-waves.pdf)
  /Creator (Cheatography)
  /Author (sams sub)
  /Subject (Communication in waves Cheat Sheet)
}

% Lengths and widths
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\addtolength{\textheight}{-1cm}
\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{FAA461}
\definecolor{LightBackground}{HTML}{FEF3EB}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Communication in waves Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{sams sub} via \textcolor{DarkBackground}{\uline{cheatography.com/167999/cs/36540/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}sams sub \\
  \uline{cheatography.com/sams-sub} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Published 15th January, 2023.\\
   Updated 15th January, 2023.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.


\begin{tabularx}{17.67cm}{x{2.6352 cm} x{4.6116 cm} x{4.6116 cm} x{4.6116 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{4}{x{17.67cm}}{\bf\textcolor{white}{.}}  \tn
% Row 0
\SetRowColor{LightBackground}
\seqsplit{Application} & Power and mode of \seqsplit{transmission} & Frequency band & How it is used and regulated \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
\seqsplit{Satellite} \seqsplit{communication} & High power signals over very long distances; \seqsplit{concentrated} by dish antennae & 1 to 40GHz \seqsplit{(microwaves)} & Satellite \seqsplit{transponders} recieve incoming upload signals, amplify them and retransmit them as a downward signal on a different frequency band \tn 
% Row Count 16 (+ 13)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{Mobile} \seqsplit{phones} & High power networked system, range several km & 800MHz to 2.6 GHz (UHF radio to microwave \seqsplit{borderline)} & 5 or 10 MHz bands allocated to different operators. 2G, 3G and 4G cellular networks offering increasing speeds for data. Higher \seqsplit{frequencies} have greater data capacity but travel less distance through air and penetrate into buildings less well \tn 
% Row Count 38 (+ 22)
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{x{2.6352 cm} x{4.6116 cm} x{4.6116 cm} x{4.6116 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{4}{x{17.67cm}}{\bf\textcolor{white}{. (cont)}}  \tn
% Row 3
\SetRowColor{LightBackground}
\seqsplit{Bluetooth} & Low power device to device links, range up to about 10m & 2.4 to 2.4835 GHz - the industrial scientific, epically (ISM) unlicensed band - borderline between UHF radio and microwave \seqsplit{frequencies} & Early Bluetooth devices interfered with Wi-Fi devices because both would use the same channel for an extended period of time. Modern Bluetooth uses frequency - hopping - i.e. \seqsplit{broadcasting} in short bursts on a number of different frequency channels across the band. This reduces the amount of data lost, and in most cases both Bluetooth and Wi-Fican maintain service \tn 
% Row Count 34 (+ 34)
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{17.67cm}{x{2.6352 cm} x{4.6116 cm} x{4.6116 cm} x{4.6116 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{4}{x{17.67cm}}{\bf\textcolor{white}{. (cont)}}  \tn
% Row 4
\SetRowColor{LightBackground}
Wi-Fi & Medium power networked system, range \textasciitilde{} 10 to 100m & {\bf{ same as Bluetooth}} & {\bf{ same as bluetooth}} \tn 
% Row Count 5 (+ 5)
% Row 5
\SetRowColor{white}
\seqsplit{Infrared} & Low power device to device links, range only a few meters & IR \seqsplit{wavelengths} 870nm or 930 to 950 nm (frequency about 320 THz) & Used for remote controls and for data transfer between computers, phones, etc. the longer wavelength band is better because it does not suffer from 'sunlight blinding'. \seqsplit{Atmospheric} moisture blocks that range in sunlight \tn 
% Row Count 26 (+ 21)
\hhline{>{\arrayrulecolor{DarkBackground}}----}
\end{tabularx}
\par\addvspace{1.3em}



\end{document}