## 4 Experiment Setup and Results
### Measuring the Height and Width of the Pulse for Various Loads  
In this section, we present our measurements with respect to the height and width of the pulse. It was observed that the width and height of the pulse vary in accordance with the applied load. To be specific, the width and height of the pulse kept increasing as the load increases. In addition, the current that is available at the output also increases up to a point and starts to fall back. In order to better understand the obtained results, the following points are summarized:  
* As shown in Figures 6 and 7a, when the resistance used is increased, the width of the pulse kept increasing. As seen in Figure 6, there has been an increase from 99.25 ms to 212 ms and to 2.955 s. In this figure, we can also observe that as the pulse is generated, the capacitor voltage (colored in yellow) decreases slowly but the decrease is no more than 0.2 V. Then, the capacitor recharges back again and generates a new pulse. Furthermore, we observed that the time between the pulses remains unchanged when the loads were changed by considering a specific distance (in this case 6 m);
* As shown in Figure 6a, due to the small Ohmic value of the load, a small amount of power is being used up by the load, and that is the reason for not attaining the maximum voltage, and also, the discharge is noticed to be very minimal. On the other hand, higher voltage values were obtained due to the increased Ohmic value of the load, as can be seen in Figure 6b,c;
* The current values versus the load can also be found by either using Ohms law or by measuring it using a current meter, as it is easier to view the current when the width of the pulse increases. Figure 6a,b have been provided as a general case for both antennas considering all the distances from 0.6 to 12 m. It can be noticed from the figures that the charging process exhibits same behavior for all resistance values. However, when the distance increases, the time taken to reach the threshold voltage increases as shown in Figure 8;
* Furthermore, as depicted in Figure 7b. at the beginning, the power source was able to provide as much voltage as the load required and consequently, the current increased. For 2000 \(\Omega\), the power source could no longer provide more voltage, thus the voltage remains constant and the current in the load starts to decrease, since \(V=I\cdot R\), therefore, if \(V\) remained constant, and \(R\) is increased, then \(I\) should decrease. To better understand this phenomena, let us recall the relationship between the charging time \(T_{ch}\) needed to charge the capacitor C, and the load resistance R which states that \(T_{ch}=R\cdot C\). Based on this relationship, higher resistance will increase the time taken for the capacitor to charge because of the higher RC time constant. Therefore, the output voltage keeps on increasing until it reaches 3.3 V which is the default maximum voltage for the built-in booster circuit. However, we can suitably adjust the RC constant by adding resistors in order to increase or decrease \(V_{set}\);
* A linear relationship is seen in Figure 7a between the pulse width and the load value. As the load connected to \(V_{out}\) increases, the pulse width of \(V_{out}\) increases proportionately. This is because the \(V_{out}\) duration depends on the capacitor discharge period. As the discharge time \(T_{disch}\) is directly proportional to the product of \(R\) and \(C\), (i.e., \(T_{disch}=R\cdot C\)), an increase in \(R\) will directly increase \(T_{disch}\). Furthermore, to quantify the measured values, for 1000 \(\Omega\) load, the width of the pulse is about 0.45 s. For 6000 \(\Omega\) load, the width of the pulse is 4 s, and with this information, we can approximate any load's pulse width (\(PW\)) with the load value \(R\) by using the following equation: \(PW=0.00071\cdot R\), where 0.00071 is the slope of the linear line between \(PW\) and \(R\).  
Figure 6: Length of the Pulse using: **(a)** 10 \(\Omega\)**(b)** 660 \(\Omega\), and **(c)** 3 K\(\Omega\).