# Wideband-Narrowband Switchable Tapered Slot Antenna for Breast Cancer Diagnosis and Treatment
## 3 Simulation and Measurement Results
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & **Wideband Antenna Type and** & **No. of Switching** & **Shape for Narrowband** & **Size of Narrowband Structure in \(\lambda_{r}\)** & **Frequency Range—Wideband and Narrowband (GHz)** \\  & **(mm\(\times\)mm)** & **Elements** & & & **Narrowband (GHz)** \\ \hline \multirow{2}{*}{[12]} & Unipazar monopole antenna & \multirow{2}{*}{2 PIN diodes 2 varactors} & \multirow{2}{*}{Ring slot resonators} & \multirow{2}{*}{0.23\(\lambda_{r}\)\(\times\)0.23\(\lambda_{r}\)} & (WB)1.33-6, \\  & & & & & (NB) 2.55, 2.6 2.8, 3.2 \\ \hline \multirow{2}{*}{[13]} & CPW del circular monopole & \multirow{2}{*}{2 PIN diodes} & \multirow{2}{*}{Split ring resonators} & Low band: 0.15\(\lambda_{r}\)\(\times\)0.15\(\lambda_{r}\) & (WB)2.5-11, \\  & & & & High band: 0.14\(\lambda_{r}\)\(\times\)0.14\(\lambda_{r}\) & (NB) 6.02, 9.18 \\ \hline \multirow{2}{*}{[14]} & TSA & 2 PIN diodes for frequency switching & \multirow{2}{*}{Split ring resonators} & \multirow{2}{*}{\begin{tabular}{} \end{tabular} } & (WB) 3.1-12, \\  & & & & (NB) 6.35 \\ \hline \multirow{2}{*}{[15]} & TSA & \multirow{2}{*}{4 PIN diodes} & \multirow{2}{*}{C-, T-shaped slots} & \multirow{2}{*}{\
\begin{tabular}{} \end{tabular} } & (WB) 1.04-3.7\(\lambda_{r}\), \\  & & & T-shape: 1.85\(\lambda_{r}\) & (NB) 0.97-1.24, 1.62-20.8, 2.64-3.71 \\ \hline \multirow{2}{*}{[16]} & Vivald antenna & \multirow{2}{*}{6 PIN diodes} & \multirow{2}{*}{Ring slot resonators} & Low band: 0.16\(\lambda_{r}\)\(\times\)0.16\(\lambda_{r}\) & (WB) 1-3.2, \\  & & & & High band: 0.16\(\lambda_{r}\)\(\times\)0.16\(\lambda_{r}\) & (NB) 1.1, 2.25, 3.1 \\ \hline \multirow{2}{*}{[17]} & Patch antenna & \multirow{2}{*}{2 PIN diodes} & \multirow{2}{*}{C-shaped slots} & \multirow{2}{*}{
\begin{tabular}{} \end{tabular} } & (WB) 5-7, \\  & & & High band: 0.06\(\lambda_{r}\)\(\times\)0.61\(\lambda_{r}\) & (NB) 5.5, 6.2 \\ \hline \multirow{2}{*}{This work} & TSA & \multirow{2}{*}{1 PIN diode} & \multirow{2}{*}{Menard line} & \multirow{2}{*}{0.11\(\lambda_{r}\)\(\times\)0.13\(\lambda_{r}\)} & (WB) 3.1-10, \\  & & & & & (NB) 2.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison with existing work. To verify the radiation characteristics of the proposed antenna in the breast phantom for a microwave imaging system, time-domain results were analyzed. In a microwave UWB radar-based imaging system, high-quality image reconstruction can be achieved when the antennas transmit and receive short-duration microwave pulses through a lossy material. In this process, a radiated pulse from the transmitting antenna passes through the breast phantom with low distortion and high efficiency. The Tx and Rx TSAs face each other through the phantom diameter (100 mm), as shown in Figure 12a. The radiated and received pulses both with and without the meander line resonator are shown in Figure 12b. By comparing the shapes between the transmitted and received pulses, it was evident that the proposed TSA exhibited low-pulse distortion characteristics, and the meander line resonator did not affect the pulse characteristic. A figure of merit for the transmitted and received signal was the fidelity factor (\(F\)), which is defined as the maximum magnitude of the cross-correlation between the observed signal at a certain distance and the excitation signal [3]:  
\[\hat{r}(t)=\frac{r(t)}{\left[\int_{-\infty}^{\infty}\left|r(t)^{2}dt\right| \right]^{1/2}}\text{ and }\hat{f}(t)=\frac{f(t)}{\left[\int_{-\infty}^{\infty}\left|f(t)^{2}dt \right|\right]^{1/2}} \tag{2}\]  
Equation (2) means the signals which are normalized to have unit energy where \(f(t)\) is the transmitted signal at the antenna terminal, and \(r(t)\) is the received E-field in the time domain. \[F= \begin{array}{cc}max&\int_{-\infty}^{\infty}\hat{f}(t)\hat{r}(t+\tau)dt\\ \end{array}  \tag{3}\]  
The fidelity factor, \(F\), is represented in Equation (3), which is determined by the peak of the cross-correlation function of the signals. The fidelity factor has a value between 0 and 1.