In present era several companies and research groups are developing enhanced technologies which help to increase the operating lifetime of battery used in wireless sensor devices. Energy harvesting from ambient radio frequency becomes an attractive and trendy solution for energizing the devices of wireless sensor networks. Abundant availability of RF power from number of cell phone towers, Wi-Fi networks and DTH transmitters ensure that ample amount of power may be harvested from ISM band and after RF to DC conversion used in various low power applications. In this paper a thorough review on existing techniques of various RF power harvesting circuit comprised of different RF to DC converter and matching network with their characteristics and applications is presented. The possibility of harvesting circuit is also explored. Authors also discussed various design issues for developing the RF energy harvester.
Read moreIn this research article designing of a multiband antenna and simulation result of the same is presented. Initially a rectangular microstrip antenna was designed and then bandwidth and other parameters along with its operating bands were modified using the modification technique which is widely known as metamaterial. Designed antenna was radiating at 2.32GHz frequency with -10dB return loss and bandwidth was very nominal i.e. 17MHz only. Later after keen literature review it was found that various techniques are available to modify such low-quality antennas. Metamaterial technique was found more superior along with the other available techniques. After implementing metamaterial parameters drastically modified, single band antenna converted into 4 bands with bandwidth of each band was greater than previous one.
Read moreRemote Malignant tumor diagnostics plays a significant role in the ability of contemporary medicine to treat cancer illnesses because early stage cancer can be treated successfully by well-developed conventional techniques. Various techniques have been used so far to design such antennas for different type of diseases. This review paper is an output of a detailed survey of various available techniques. The objective of this paper is to provide an overview of these challenges, a nd discuss the ways in which they have been dealt with so far in the literature.
Read moreThis paper proposes a novel switched-capacitor inverter. The switching operation of the capacitors in series and in parallel produces larger voltage than the input voltage in the proposed inverter. Based on the number of the capacitors the maximum output voltage is determined. In the conventional unit both boost converter and an inverter bridge are present whereas the proposed inverter does not need any inductors thus it is smaller than the former one. And also produces fewer harmonics compared to conventional one. The circuit configuration and the simulation results are shown in this paper. The simulation is done with MATLAB/ SIMULINK software.
Read moreIn this paper a hybrid amplifier EDFA-RAMAN DWDM transmission system is proposed and demonstrated. A new hybrid two-stage optical fiber amplifier for dense wavelength division multiplexing (DWDM) network is observed. The hybrid amplifier is cascaded erbium- doped fiber amplifiers (EDFA) & Raman amplifier which provide a nearly flat gain over 80 nm. The hybrid amplifier has been modeled using an Optic-System version 14 on a DWDM transmission. In this paper we compare Q-factor at different input power i.e. at 0db and at 10 db. Here two different types of apodized function (Uniform & Gaussian) are selected as fiber Bragg grating parameters and system performance is analyzed. Performance of the system is analyzed by using BER analyzer.
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