Joydeep Sengupta

Magnetic Induction-Based Non-Conventional Media Communications: A Review

The magnetic induction (MI)-based communications assume the applications, wherein standard electromagnetic (EM) wave and acoustic communications are not effective. The EM and acoustic-based communications do have high power loss, high propagation delays, very low data rates, and environment-dependent channel behavior. MI communications heavily depend upon the time varying magnetic field to convey information between transmitter and receiver. MI-based communications for non-conventional media (e.g., underwater or underground) exhibit several unique and promising qualities, such as constant channel behavior, negligible propagation delay, and large communications range. This paper surveys the current state-of-the-art magnetic induction-based communications for non-conventional media applications. The widely used communications techniques for non-conventional media are qualitatively compared. In particular, the advantages and the disadvantages of different communications techniques are analyzed in terms of different performance metrics. In addition, we highlight some important open issues related to the design of MI for non-conventional media. This survey aims to provide a useful guidance to the researchers in this area.

Measurement of noise and efficiency of 4H-SiC IMPATT diode at Ka-band

In this paper, different DC parameters such as the efficiency, voltage drop along the diode, quality factor, resistance and the noise measurement on a one dimensional n+npp+ DDR structure of 4H-SiC-based IMPATT diode have been studied using advanced computer simulation programme. The efficiency and noise measure vary with the operating frequency of the IMPATT diode. The efficiency as well as the noise measurement plays an important role in the choice of operating frequency. So, throughout the Ka band these parameters of the 4H-SiC IMPATT Diode are measured and compared and will be well suited for the optimum design in the Ka-band.

Space Charge Effect of IMPATT Diode Using Si, Ge, GaAs, InP, WzGaN and 4H-SiC at Ka-Band

ABSTRACT Extra space charges are generated in the drift region due to the avalanche multiplication process and space charge effect of IMPATT (impact ionization and avalanche transit time) diode reduces the efficiency of the devices. The disturbances in electric field, drift voltage, and space charge resistance represent the space charge effect. In this paper, a comparative study of these disturbances has been presented for silicon, germanium, gallium arsenide, indium phosphide, WzGaN (wurtzite gallium nitride), 4H-SiC (silicon carbide) semiconductor materials-based double drift region (DDR) IMPATT diode at Ka-band as well as the cause of poor efficiency in the diode highlighted. This will be helpful for the selection of the suitable material for optimum design of DDR IMPATT diode as well as to improve the DC to radio frequency (RF) power conversion efficiency.

Biosignal Acquisition System for Stress Monitoring

In this paper, it focus on the acquisition of biosignals like electroencephalogram and heart rate and study their relation with stress levels of a person. A common day-to-day life situation of car driving and a few stress causing elements to see this relation have been picked up. We have used a car racing simulator for this purpose, with varying traffic levels, different tracks (straight and with turns) as well as varying number of opponents to vary the stress developed on the driver. These signals were procured using our hardware, then interfaced to the LabView using Atmega 16 development board. 2 Virtual Instruments were built to help in analyzing the signals acquired-(i) used to filter the ocular artifacts from EEG using RLS-wavelet method. (ii) was used to separate out the various components of the EEG signals. We further try to correlate frequency of eye-blink rate, components of EEG and their presence with the stress level developed. We found that the stress levels of a person measured in terms of eyeblink rate, heart rate showed an increase in stressful situations (increase in traffic and number of turns, crashes, introducing obstacles, etc). The various components of EEG were also separately studied to find if a person is relaxed. Finally, a statistical model was produced to combine these results and make a decision on whether a person is stressed. This line of research may be very useful to society.

Optimal Clustering in Weibull Distributed WSNs Based on Realistic Energy Dissipation Model

In this paper, a realistic energy consumption model of sensor node has been provided by considering eleven key energy consumption sources, some of which are ignored by contemporary energy consumption models. Clustering is a technique by which we can reduce energy consumption of networks. Optimizing the number of clusters improves the scalability of system, reduces the system collisions and delays. To this end, we proposed a realistic energy consumption model of a sensor node, by using that, provided an analytical expression for finding the optimal number of clusters in a Weibull distributed WSNs.

Ka band noise comparison for Si, Ge, GaAs, InP, WzGaN, 4H-SiC-based IMPATT diode

ABSTRACT A comparative study of small signal noise has been presented for n+-n-p-p+ double drift region (DDR) impact avalanche and transit time (IMPATT) diode. The comparison is made by taking different semiconductor materials such as silicon, germanium, gallium arsenide, indium phosphide, wurtzite gallium nitride and 4H-silicon carbide, as doping element throughout the Ka band frequency of 26.5–40 GHz. Also, a generalised idea for performing the small signal noise analysis for the IMPATT diode is presented, by taking a one-dimensional mathematical model of DDR IMPATT diode. The 4H-SiC material-based IMPATT diode is proven to be less noisy with noise measure (NM) variation of 17–29 dB in the Ka band, whereas Ge-based IMPATT diode is noisier with the NM value of 34–44 dB. This paper has studied the small signal noise behaviour and is helpful in selecting the proper semiconducting material for the optimum design of the IMPATT diode in the Ka band.

Design of a via-less, compact CPW-fed ZOR antenna for WLAN Applications

A single layer, low profile, compact metamaterial zeroth-order resonator (ZOR) antenna has been proposed in this paper. A composite right/left-handed (CRLH) transmission line structure that is comprised of a single unit cell makes up the complete antenna. The design complexity of the proposed antenna is very low, since it does not involve any vias. A symmetric coplanar waveguide (CPW) structure is chosen to have design flexibility and to satisfy the design constraints. The main aim of incorporating the left handed behaviour into the design is to achieve compactness. The resonant frequency of zeroth-order mode is around 5.8GHz. A prototype of the proposed antenna has been fabricated and it has the dimensions of 0.348λo × 0.309λo × 0.033λo. The simulated peak gain of the antenna is found to be 0.65dBi. A significant amount of size reduction is observed in the patch area of proposed structure when compared to a regular patch antenna operating at the same frequency. The metamaterial behaviour has been verified with the help of dispersion diagram and vector electric field plot. Simulation is done so as to plot the reflection coefficient of the presented CPW ZOR antenna and it is also observed on the vector network analyzer (VNA). Simulation results show that the proposed ZOR antenna achieves −10dB impedance bandwidth of 7.76% and has a radiation efficiency of about 81.27% at the ZOR mode.

GPS and GSM based rail signaling and tracking system

In this paper, we propose a system for monitoring, tracking, and automating the trains. In contrast to the existing methods, we employ a global position system (GPS) and Global System for Mobile communication (GSM) by which each train is individually monitored and necessary messages are passed on proactively. The proposed system has advantages in terms of communication range and accuracy with respect to Zigbee, Wi-Fi, RFID based rail tracking method. The work has potential applications in bad weather and emergency situations like collision.