This paper describes the modelling process the dual channels SFCW signal generation using LabVIEW software. The developed signal generator can be used for any frequency range as well as single or dual channels. The designed user interface was kept as simple as possible. The dual channel SFCW signal generator was tested using two frequency range: 1MHz to 401MHz and 401MHz to 801MHz for channel one and two respectively. Both channel of stepped-frequency continuous wave (SFCW) radar signals has 400MHz bandwidth and divided into 8 steps with 50MHz of frequency step size. The aim of this paper has been achieved. A simulation of dual frequency channels SFCW signal generator is implemented in LabVIEW software. The SFCW waveform from both channels have been deconstructed and the frequencies component present in the generated SFCW waveform has been plotted which reflect the calculated frequencies components of 1MHz, 51MHz, 101MHz, 151MHz, 201MHz, 251MHz, 301MHz, 351MHz for channel one and 401MHz, 451MHz, 501MHz, 551MHz, 601MHz, 651MHz, 701MHz, 751MHz for channel two. The SFCW radar system are designed to generate the signals concurrently.
In this paper, metamaterial unit cell integration with antenna is presented. This sensor aims to improve the directivity of the previous sensor. As a proposed design, adding metamaterial in front of the antenna will help increase the direction. The overall dimension of the proposed antenna is 61.03 mm×70 mm. It can be seen that earlier, the sensor was resonating at 3–7.19 GHz in the simulation and 3–7.28 GHz in the measurement. The return losses at these frequencies were around 28.9 dB at 6.78 GHz in the simulation and 3.78 GHz in the measurement, respectively. After placing the of two SRR were aligned from the endfire end for Design B, it was found from the simulated result that the return loss dropped significantly to around −43.3 dB at 4.12 GHz in the simulation and −30 dB at 4.4 GHz in the measurement. Reflection coefficient, radiation pattern, gain, efficiency, and directivity were the sensor parameters analyzed to determine the metamaterial performance. The gain of the metamaterial sensor is increasing by 1.29 dBi in simulation and 2.88 dBi in measurement. The directivity of the sensor also increases by 1.45 dBi in simulation and 1.71 dBi in measurement. In a nutshell, the proposed sensor can be used for microwave imaging applications.
Many types of conventional antennas exist for RF energy harvesting purposes. This energy can be used for sensor applications. The microstrip patch antenna is a more efficient and better radiation antenna that can be chosen out of all antennas since it is smaller in size and operates at microwave frequencies. This work presents the parameter design, simulation, and output testing of a microstrip patch antenna that can harvest energy from the Wi-Fi with the resonance frequency of 2.4 GHz. This antenna is a good radio frequency harvester that can absorb the energy spectrum in the band of interest for Wi-Fi and Wi-Max. The simulation of the microstrip patch antenna was performed using Computer Simulation Technology (CST) and the results obtained are discussed. The return loss of the antenna will also be discussed using the simulation result. In the fabrication of the antenna, the patch shape of the antenna was laser printed first using a photo sheet and then was printed on the copper board. Finally, by using thinner, the shape of the patch was obtained. The specialty of the microstrip patch antenna is the antenna design itself has the impedance matching feature where we make the 1 mm gap between the inset feed and the patch. Further, an SMA connector was used at the feeding point of the antenna since it can feed 50 Ω characteristic impedance. The minimum voltage expected from the antenna is 0.3 V ac. Finally, the antenna output voltage was tested at various places. The voltage differs according to the Wi-Fi strength of the place. The output voltage increases when the Wi-Fi strength is relatively higher.
Diabetes is one of the world-leading lethal diseases that have no cure, but it is manageable to prevent further deterioration. The in vivo non-invasive glucose monitoring method can be a key to aid the diabetes patient in monitoring the glucose level effectively in the future with the features of cost-effectiveness, painless and minimum infection. In this paper, the dielectric measurement technique has been applied to obtain the relationship between dielectric properties and the in vivo blood glucose concentration on a human subject. An open-ended coaxial sensor is used to measure the EM parameters at various blood glucose concentrations by placing them on Pulse, Thumb and Finger. The measurement data have been collected and compared to the commercial invasive glucose meter. The characterisation and modelling have been performed with a few selected frequencies at 1GHz, 2GHz and 4GHz. Based on the analysis, the dielectric constant drops and the loss factor rises as the glucose level increases. The models have been validated, and the performance has been analysed. It was showed that the Pulse is the optimal position to apply for the non-invasive blood glucose measurement.
Fog radio access network (F-RAN) is an emergent technology that provides a cloud-like services to the end nodes (ENs) at the edge of the network. Reducing the transmission delay is of a great importance to boost the performance of F-RAN, which can be achieved by optimizing the probability of FNs. In this context, this paper proposes a framework to obtain the optimum the probability of FNs that minimizes the transmission delay in a finite F-RAN. The proposed approach shows that the optimum probability of FNs is the real root of a polynomial equation of a degree determined by the path loss exponent (PLE). The results show that optimizing the probability of FNs can significantly reduce the transmission delay. Moreover it shows that the optimum probability of FNs decreases with the PLE and number of deployed nodes.
