I have been trying to insert the table of dimensions of an antenna in a latex code. I used the code
\begin{table}[h]
\centering
\begin{tabular}{l | l | l | l | l}
Reference Number & BW (GhHz) & Antenna size (mm3) & Gain & Notched Bands (GHz) \\
\hline
[20] & 2.3-13.75 & 39*39*1 pt 6 & 1 pt 4-46 & 2 pt 25-3.75
5.08-5.9
7.06-7.95
\\
[21] & 3.11-13.15 & 28*52*1.6 & 1.53-4.05 & 5.1-5.92 \\
[22] & 2.8-14 & 27*36*1.6 & N/A & 3.26-3.9
4.35-5.05
5.5-6.35
7.95-9.35
\\
Current Work & 3.1 – 17 & 24*28*1.6 & 4.5-8 & 3.2-3.9
7.2-8.5
\end{tabular}
\caption{Comparison of the suggested antenna to antennas in previous litrature}
\end{table}
\end{document}
but the error:
\begin{table}[h]
\centering
\begin{tabular}{l | l | l | l | l}
Reference Number & BW (GhHz) & Antenna size (mm3) & Gain & Notched Bands (GHz) \\
\hline
[20] & 2.3-13.75 & 39*39*1 pt 6 & 1 pt 4-46 & 2 pt 25-3.75
5.08-5.9
7.06-7.95
\\
[21] & 3.11-13.15 & 28*52*1.6 & 1.53-4.05 & 5.1-5.92 \\
[22] & 2.8-14 & 27*36*1.6 & N/A & 3.26-3.9
4.35-5.05
5.5-6.35
7.95-9.35
\\
Current Work & 3.1 – 17 & 24*28*1.6 & 4.5-8 & 3.2-3.9
7.2-8.5
\end{tabular}
\caption{Comparison of the suggested antenna to antennas in previous litrature}
\end{table}
\end{document}
kept showing. How can I simply insert the dimension of an item in a table.

[20],[21]and[22]in curly braces :{[20]},{[21]}and{[22]}. – Zarko Jan 01 '23 at 07:00\hlineis picked up as an optional argument, which has to be a dimension. Using braces as suggested by @Zarko will prevent this. – Ian Thompson Jan 01 '23 at 07:58$\[...\]$and$\leftbracket ... \rightbracket$. – John Kormylo Jan 01 '23 at 18:14