## 2 System Requirement
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Ref.** & \begin{tabular}{c} **Antenna Size** \\ **(in mm)** \\ \end{tabular} & \begin{tabular}{c} **Frequency** \\ **(GHz)** \\ \end{tabular} & \begin{tabular}{c} **Substrate/Conductor** \\ **Material** \\ \end{tabular} & \begin{tabular}{c} **Patterns** \\ **Circuit** \\ \end{tabular} & \begin{tabular}{c} **Electronic** \\ **Efficiency** \\ \end{tabular} & \
\begin{tabular}{c} **Gain (dB)/Radiation** \\ **efficiency** \\ \end{tabular} &
\begin{tabular}{c} **Range** \\ **Bending/Wet** \\ \end{tabular} \\ \hline
[27] & \begin{tabular}{c} 40\times 40 \\ Modular Button \\ \end{tabular} & 2.40/5.30 & \
\begin{tabular}{c} Cuming-Foam- \\ PF4/Shieldit \\ \end{tabular} & O & NA &
\begin{tabular}{c} 7.80/3.10 \\ (Half-Wave)/NA \\ \end{tabular} & NA & NA \\ \hline
[28] & \
\begin{tabular}{c} 40\times 40 \\ Modular Button \\ \end{tabular} & 4.75-5.25 &
\begin{tabular}{c} Cuming-Foam- \\ PF4/Shieldit \\ \end{tabular} & C & NA & NA & NA & NA \\ \hline
[29] & \begin{tabular}{c} 100\times 100 \\ Circular Button \\ \end{tabular} & 2.40 & \
\begin{tabular}{c} FR4, Felt \\ /Copper, ShieldIt \\ \end{tabular} & O & NA &
\begin{tabular}{c} FS,OA \\ 1.80/5.10, and \\ 97.00/71.00 \\ \end{tabular} & NA & NA \\ \hline
[30] & \
\begin{tabular}{c} 18 (Diameter) Button \\ Antenna with Frequency \\ Selective Surface \\ \end{tabular} & 5.25-5.85 &
\begin{tabular}{c} Acrylic \\ Transparent/Copper \\ \end{tabular} & B & NA & 2.10 & NA & NA \\ \hline
[31] & \begin{tabular}{c} Conical-helix \\ Button-Antenna \\ \end{tabular} & 3.00/5.80 & \
\begin{tabular}{c} Copper Surface \\ \end{tabular} & O/B & NA &
\begin{tabular}{c} 2.30,8.00/NA \\ 2.30,8.00/7 NA \\ \end{tabular} & NA & NA \\ \hline
[32] & \begin{tabular}{c} 100\times 100 \\ Circular Button \\ \end{tabular} & 5.50 & \
\begin{tabular}{c} FR4, Felt/Copper, ShieldIt \\ \end{tabular} & O & NA &
\begin{tabular}{c} FS,OB \\ 79.90/70.80,3.50 \\ \end{tabular} & NA & NA \\ \hline
[33] & \begin{tabular}{c} 80\times 80 \\ Circular Button \\ \end{tabular} & 2.40/5.00 & \
\begin{tabular}{c} Rogers 5880, \\ Felt/Copper, ShieldIt \\ \end{tabular} & O & NA &
\begin{tabular}{c} FS,OB (Lower/Upper \\ bands); 90/84.10, \\ 0.24/45.04,7.33 \\ \end{tabular} & NA & A \\ \hline
[34] & \
\begin{tabular}{c} 22.3 (Diameter) \\ Circular-Cuff Button \\ \end{tabular} & 2.40/5.60 & PTFE/Copper & O & NA &
\begin{tabular}{c} Free Space \\ 1.50/94.00 \\ \end{tabular} & NA & NA \\ \hline
[35] & \begin{tabular}{c} 100\times 100 \\ Circular-Array Button \\ \end{tabular} & 4.50-4.61/ \
\begin{tabular}{c} Cuming-Foam (PF4) \\ RO4003/Copper \& \\ ShieldIt \\ \end{tabular} & B & NA &
\begin{tabular}{c} 7.70/NA \\ \end{tabular} & 20 mm & NA \\ \hline
[36] & \begin{tabular}{c} 100\times 100 \\ Inverted-F Button \\ \end{tabular} & 2.45/5.80 & RO4003/Copper & O & NA & \
\begin{tabular}{c} OB (Lower/Upper \\ bands); -0.60/430 and \\ 46.30/69.30 \\ \end{tabular} &
\begin{tabular}{c} 18-122 \\ cm \\ \end{tabular} & NA \\ \hline
[37] & Dipole Sensor Antenna & 2.40 & FR4/Copper & AZ & A & 2.40/28.00 & 1.5 m & NA \\ \hline
[38] & GPS Tracking Antenna & 2.40 & FR4/Copper & U & NA &
\begin{tabular}{c} 3.00/NA \\ 3.00/NA \\ \end{tabular} & NA & NA \\ \hline
[39] & \
\begin{tabular}{c} 70 (Diameter) \\ Patch Antenna \\ \end{tabular} & 2.40/5.80 & PDMS/ShieldIt & M & NA &
\begin{tabular}{c} OB (Lower/Upper \\ bands); 4.16/4.34, 58.6 \\ \end{tabular} & NA & NA \\ \hline
[40] & \begin{tabular}{c} 50\times 57 \\ Steve-Bidge Antenna \\ \end{tabular} & 2.45 & \
\begin{tabular}{c} Multilayered \\ Textile/ShieldIt \\ \end{tabular} & O & NA &
\begin{tabular}{c} \(-2.33\)/55.3 \\ \end{tabular} & NA & NA \\ \hline
[41] &
\begin{tabular}{c} 130\times 130 \\ Circular Patch with Soft \\ Periodic Surface \\ \end{tabular} & 4.00 & Felt/Shielder Zell RS & B & NA & NA & NA & NA/NA \\ \hline
[42] & \
\begin{tabular}{c} 70\times 25 \\ Loop Dipole \\ \end{tabular} & 2.36-2.39 & PDMS/Copper & O & NA &
\begin{tabular}{c} FS (OB) \\ 0.68 (\(-0.40/15.00\)) \\ \end{tabular} & NA & NA \\ \hline
[43] & \begin{tabular}{c} 37.20 \times 50 \\ MMA \\ \end{tabular} & \begin{tabular}{c} 2.2 to \\ 6.0 \\ \end{tabular} & Felt/ShieldIt, Copper & O & NA & \begin{tabular}{c} OB Chered and OA (L/U) \\ 3.30 (\(4.67\)) and 3.300 \\ (\(4.55\)); 54.37 (\(54.27\)), \\ and 60.0 (\(63.73\)) \\ \end{tabular} & \
\begin{tabular}{c} 11 m \\ A \\ \end{tabular} &
\begin{tabular}{c} A \\ 11 m \\ \end{tabular} & A \\ \hline
[44] &
\begin{tabular}{c} 94.58 \% 52.36 \\ Patch \\ \end{tabular} & 1.80-2.40 & Felt/ShieldI & D & NA & NA/50.00 & NA & NA \\ \hline
[45] &
\begin{tabular}{c} 50\times 50 \\ Graphene Antenna \\ \end{tabular} & 3.13\(-\)4.42 & Graphene/Poly:t & O & A & NA & NA & NA \\ \hline
[46] &
\begin{tabular}{c} 80\times 60 \\ Patch \\ \end{tabular} & 2.00-4.00 & Cellulose Filter paper & NA & NA & NA & NA & NA \\ \hline
[47] &
\begin{tabular}{c} 71\times 64 \\ Patch \\ \end{tabular} & 2.45 & Cotton Jeans & NA & NA & NA & NA & NA \\ \hline
[48] & \begin{tabular}{c} 40\times 40 \\ Reconfigurable Button \\ Antenna \\ \end{tabular} & 2.45/5.80 & PDMS, textile/Copper & B & A & \begin{tabular}{c} 0.70\(-0.90\), and \\ 43.80/73.80 \\ \end{tabular} & NA & NA \\ \hline Pro & \begin{tabular}{c} Button Antenna: \\ 45 (Diameter) \\ Dual-band Sensor Module \\ \end{tabular} & 2.45/5.6 & \
\begin{tabular}{c} PCB Button, Felt/Shield \\ (Substrate/Ground), \\ PCB Module. \\ \end{tabular} & O/B & A &
\begin{tabular}{c} (Lower/Upper \\ bands); 0/84.10, \\ (\(5.670\))/65.12 (\(81.63\)), 75 \\ (\(\overline{85}\)) \\ \end{tabular} & 40 m & A \\ \hline  & & & & & & \\ \end{tabular}
\end{table}