RAHUL KRISHNAN
@mbcpeermade.com
Assistant Professor, Electronics and Communication Engineering
Mar Baselios Christian College of Engineering & Technology
RESEARCH INTERESTS
Antenna Design, IoT, Wireless Networks, Microwave Imaging
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Melbin Elsa Cheriyan, Rahul Krishnan, Ramu R, Glintu Joy, Abina Ann Mathew, and Shefin Shaji
IEEE
The fields of biomedicine and healthcare have recently shown a great deal of interest in the investigation of flexible wireless devices. Human bodies produce a tremendous amount of information. Therefore, we present a small, slotted hexagonal patch antenna for use in biomedical applications. Lightweight and semi-flexible Rogers RT duroid 5880 material is used in the antenna’s construction. The incorporation of slots and partial ground structure aided in boosting the operating performance of the antenna. Using Computer Simulation Technology (CST) software, the proposed antenna’s performance is evaluated in terms of bandwidth, return loss, gain, radiation pattern, directivity, total efficiency, and power.
Dharmeshwaraan K, L. Saravanan, P. Sharmila, Rahul Krishnan, Shyam. M, and Anitha G
IEEE
Since the advent of low-cost and low-power sensors, Wireless Sensor Networks (WSNs) have exploded in popularity, leading to substantial advancements in wireless communication. However, since WSN nodes rely on batteries for power, they lose all independence after a set period of time. The lifespan of the network is impacted by the need to save energy. It is possible to extend a network's useful life while simultaneously decreasing its power consumption via the process of clustering. Using clustering, a group of similar sensors may be gathered in one place to collect and transmit data to a central hub (BS). When gathering and transmitting data, Cluster Head (CH) consumes more power. Energy consumption may be reduced and WSNs' lifespan increased with accurate CH detection. There is still a lot of effort to be done in developing a routing algorithm that takes into account the main difficulties of minimizing energy consumption and optimizing network longevity. In order to address these crucial problems in WSNs, this study introduces a clustered routing protocol that minimizes energy consumption by using a Mayfly-Aquila optimization (MFAO) method. To choose the best candidate for CH, the Mayfly algorithm is used. The good possible way from CH to BS is determined using the Aquila optimization algorithm and chosen at random. Based on the simulation findings, it is clear that the suggested technique may significantly reduce energy consumption compared to the current state-of-the-art methods.
S. Vanaja, R. Preetha, J. Joselin Jeya Sheela, K. Durga Devi, Gayathry Sobhanan Warrier, and Rahul Krishnan
Bentham Science Publishers Ltd.
Background: Universally, the most predominant cause of female mortality is mainly due to breast cancer. Owing to numerous constraints in the existing imaging technique, researchers are trying out an alternative tool to detect the tumor before going to the miserable stage. Methods: This article presents a novel method to detect the mean value system for detecting the location of the tumor in different depths by shifting the antenna anywhere in the breast tissue. In addition, an algorithm to reconstruct the breast image, namely Delay-Multiply-and-Sum (DMAS) is followed to identify the tumor implanted in the breast tissue. Results: The analysis shows that the maximum mean value occurs while the antenna moves very near to the tumor while the mean value reduces while the antenna shifts apart from the tumor location. The mean value in different locations is converted into a microwave image. The high intensity in the image exhibits the precise position of the tumor. This technique can identify the location of early-stage tumor of size 3mm. Multiple tumors of sizes 6mm and 7mm can identify at a depth of 12mm and 18mm in the homogeneous breast phantom. DMAS can provide better imaging results in the early stage tumor of size 3mm embedded in the breast phantom. Conclusion: Microwave imaging is an efficient technique to differentiate healthy and malignant tissue in the breast. Antenna plays a major role in identifying tumors in the breast in the early stage. Hence a high-performance Ultra Wideband Dielectric Resonator Antenna (DRA-UWB) is used to identify the tumor in the breast. An antenna is sketched in different locations of the breast phantom. On account of the hemispherical structure, the mean value of the reflected signal is high at the center than at the edge. Hence, the difference in mean value is calculated with and without breast phantom for identifying the tumor location. The overall efficiency of this technique can be improved by using a high-performance UWB antenna. The image of the breast is reformed by the DMAS beamforming algorithm.
R. Ganesh Babu, D. Lavanya, L. Raja, S. Velmurugan, N. Nalini, and Rahul krishnan
AIP Publishing
A. Balaji, B. Sathyasri, Vijaya Vardan Reddy S, D. Indumathy, Rahul Krishnan, and S. Vanaja
IEEE
The aim of the proposed work is to identify the moving human beings in a smart home security system. In the conventional home monitoring arrangement, Closed-Circuit Television (CCTV) is used which exactly record the videos without giving any feedback to the house owner if any suspected person there. Therefore, there is a need of moving object detection system and warning system for the safety of senior citizen in the home. The proposed hardware architecture is carried out using Arduino and Raspberry Pi 3 processor. The Raspberry Pi 3 process the images received through the Passive Infra Red (PIR) sensor and webcam assembled on Raspberry Pi 3. The PIR sensor activates the webcam, if any movement is detected around the sensor. The captured image is compared with two frames, if any motion is detected immediate alert in the form of call and mail is shared to the house owner in addition to the detected the motion object image.
V. Ramkumar, Supraja C, V. Chinnammal, Rahul Krishnan, L. Saravanan, and J.Joselin Jeya Sheela
IEEE
In this article, a stacked elliptical to circular shape Dielectric Resonator Antenna (DRA) is designed to act as sensor in breast tumor detection in the imaging (MWI) technique. The novelty of the proposed article is different size of elliptical to circular shape DRA is excited by inset feed mechanism. Two different iterations are followed to improve the performance by varying the elliptical dielectric structure of dimensions in the x-axis by = 3mm, 6mm. Later, circular DRA of radius 9mm is proposed to improve the bandwidth of the antenna. The DRA substrate layer is designed using FR4 material (εr=4.2) and the elliptical dielectrics iterations are made of alumina (εr=9.8). In addition the improvement in bandwidth is due the invasion of wheel structure in the ground plane. From the result it is observed that the antenna resonates at nearly 1.7 GHz, 2.4 GHz, 3.7GHz and 10.1GHz which comes under X-band, S band and L-band frequency range. A significant variation of return loss is identified in the analysis when the dielectric structure is varied from elliptical to circular structure.
Rahul Krishnan and Jobin Christ M.C
Bentham Science Publishers Ltd.
Aims: This work was focused on the detection of early-stage breast tumors and their location. Background: The most frequently seen disease progression and mortality in women's lives is Breast Cancer. Because of breast cancer/tumors, the risk of mortality for women has risen exponentially. From the 2020 deadline for breast cancer, women who died from carcinoma were 123.8 cases per lac women between 2006-2010. This problem is also overcome by the early identification of the tumor using different detection procedures like X-ray mammography, computerized tomography, ultrasound imaging technique, Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), microwave imaging. Researchers carried out multiple studies in these areas. Objective: To detect early-stage breast tumors and their location using SAR analysis. Methods: The major dielectrical difference between cancerous breast tissues and normal tissues in this technique is the microwave frequency range. The term Specific Absorption Rate (SAR) describes the amount of energy which is absorbed (W/kg) in the breast tissue. This segment illustrates the usefulness to diagnose the tumor position in the breast by means of maximum SAR value coordinates. Changes in breast and tumor size are important for the risk of diagnosis. The power absorbed in connecting with a normal breast and a tumor breast is measured and equivalent for different breast masses. The maximum SAR is also analyzed at distinct tumor locations at various frequency ranges. Results: It is observed that max SAR coordinates are very close to the actual tumor location. So, the maximal value of SAR coordinates indicates the existence of a tumor in the breast phantom. Conclusion: The simulated data above strongly suggests that the Max SAR values were higher in the breast phantom with tumor as compared to the breast without tumor. With different tumor radius (3 mm and 5 mm) analyzed with different resonant frequencies like 3GHz, 4GHz and 5GHz at the actual tumor location of (0, 0, 35). Even though a model representing the real properties of breast tissue is required to assess the validation of any imaging process, so the real-time development of an equivalent breast phantom and its execution is needed.
J.Joselin Jeya Sheela, S Kalaivani, B. Jeyapoornima, S. Vanaja, Rahul Krishnan, and Y. Deepika
IEEE
In recent years, the broadband networking and wireless communications are using miniaturized and light weighted multiband antennas. Smaller sized antennas can able to provide the same efficiency as like huge antennas while costing less and allowing for greater device integration. The multiband microstrip patch antenna is designed to multiply the entire system capacity for transmission and reception. A miniaturized multi band antenna is designed to operate at 5,6.2,8,9.8,11.1 and 13.5 GHz by modifying the existing rectangular micro strip patch antenna design pattern. The proposed antenna is also working to reduce unwanted noise frequency. The Computer Simulation Technology simulation software is used as a platform for antenna design and its performance analysis. The antenna efficiency is proved through return loss, radiation pattern, impedance matching and voltage standing wave ratio (VSWR) measurements. For antenna fabrication, FR4 substrate is considered as dielectric component and copper annealed is chosen for patch. The presented antenna design is used for RF applications such as transmission and reception of communication devices, wireless devices for military applications.
Vijaya Vardan Reddy SP, B. Sathyasri, A. Balaji, S. Vanaja, Rahul Krishnan, and Y. Deepika
IEEE
The main objective of the system is to monitor the vehicles that are entering and going out of the organization. All vehicles have their own unique license plate number, so the abstraction of plate number plays a major role in this system. The vehicle number plate is taken by the tool like camera which is placed at the entrance. The captured image is then processed by the Automatic Number Plate Recognition (ANPR), an image processing algorithm. ANPR method is an efficient way of recognizing the vehicle numberplate and strengthen the security system. A database is created with the vehicle number which belongs to that particular organization. The recognized number plate is then compared with the database and checks whether the vehicle belongs to the organization if not then it is an unknown vehicle. Then the entry and exit time of the organization vehicles are recorded. In case of centralized receiver all the entrance records are kept in storage and any unfamiliar vehicle entering into the organization is noticed and central controller monitor the details.
B. Jeyapoornima, V. Chinnammal, S. Vanaja, J.Joselin Jeya Sheela, Rahul Krishnan, and Y. DEEPIKA
IEEE
The Fetal movements for each women's are exclusive for each individual fetus. The existence of healthy nature of the fetus is in the comfortable zone. In addition the healthy nature of the pregnancy is based on the movement rate, strength and frequency of the motion. The reduced fetal movement indicates, pregnancy women have reduced fetal growth, stillbirth and pre-term birth. The important information required by the pregnant women is to give alert about the regular fetal kicks otherwise reduced fetal movements indicates a risk of fetal hypoxia. The outcome of a pregnancy is based on the frequency and intensity of the fetal movements. So, here in this project a meander line antenna is designed in order to detect the fetal actions.
A. Balaji, Rahul Krishnan, S. Vanaja, Sowmiya T, Ramya Bharathi T, and Vanitha R
IEEE
This article focuses on a polarization - freelance Tri- stop band FSS in case of sensible medical instrument approach. FR-4 substrate is used to construct Frequency Selective Surface (FSS) structure, using that behavior FSS act as a band stop filter for the frequencies of 2.4 GHz, 1.8GHz and 5GHz. The three band-stop frequency area unit severally controlled by standardization the building block mathematical framework. The building block manifest a consistent form in order to alter constant affording in each mode of TE and atomic number (0°_60°) for the wave incident and also the stability of the system at different angles are verified. The simulation result is analyzed for the TE and TM mode polarization coefficient and Transmission coefficient for the incident angle varies from 0° to 60°. The high frequencies stop band response achieved by increasing the angle of incident. The planned building block configuration is created by the use of CST studio software. The characteristics of tri band FSS is confirmed by matching it with the simulation result.
S. Rosaline, Kannan K, Rahul Krishnan, S. Vanaja, and J. Joselin Jeya Sheela
IEEE
An Ultra-wideband (UWB) pentagon antenna is examined and simulated using CST microwave studio for detecting the tumor present in the brain. It is operating at the range 3.67GHz to 13.2GHz in free space. The substrate of the microstrip antenna is designed using Flame Retardant (FR-4) substrate. The dimensions of the antenna are $44\\times 30\\text{mm}$. For improving the bandwidth and directivity modifications is made in the patch and ground. The input radiations from the antenna are allowed to penetrate into the human head phantom containing tumor and the reflection coefficient is analyzed. The result shows that tumor head phantom has high reflection compared to tumor free model.
B. Jeyapoornima, J. Joselin Jeya Sheela, C. Malarvizhi, S. Vanaja, Rahul Krishnan, and Rajasekhar Atla
IEEE
In the recent days, wireless communication has established in a popular increased rate. The antenna prototype is having numerous band abilities which can be used in various many wireless technologies. The proposed double operating band patch antenna in the field of 5G/WLAN/WiMAX communication. In this paper, FR4 has been used as a substrate material with relative permittivity, $\\mathcal{E}\\mathrm{r}=4.2$ as whose thickness is mm. The planned double operating band antenna is simulated and analyzed using HFSS software. The planned antenna has very high isolation in the field of MIMO systems and due to miniaturized size ($17.56\\text{mm}\\times 12.56\\text{mm}$) it is suitable to use in mobile phone. The analysis shows that reflection coefficient of the proposed antenna is having less than −10 dB, better gain and good bandwidth using miniaturized size of the antenna.
Rahul Krishnan, R Ganesh Babu, K. Lalitha, Rajasekhar Atla, Vanaja. S, and Swetha. D
IEEE
This paper introduces a compact dual bandstop frequency selective surface (F.S.S.) for shielding applications. The octagonal and square looped model projected in this paper act as a band rejects filter for the frequencies 2.4 GHz and 5 GHz. The proposed model simulated using CST MWS electromagnetic simulation software. The current distribution for the two resonance frequencies is analyzed well. The proposed unit cell provides a symmetrical shape which enable stable performance in both T.E. and T.M. mode. The angular stability was assessed in various angles of incidence from (0°–60°). In T.E. polarization, the transmission and reflection coefficient for second resonance frequency shifted by +0.5 GHz and −0.5 GHz.
L. Raja, A. Farithkhan, K. Vijayalakshmi, T. Sripriya, Rahul Krishnan, and Keren Naomi Devnesh
IEEE
This paper describes the simple design of a dielectric resonator antenna for 2.4 GHz using a regular cubic resonator for biomedical applications. Dielectric resonator antennas (DRAs) are used at microwave and millimeter frequencies and consist of materials having a high dielectric constant that have high gain and directivity. The resonator is placed upon a copper-grounded fire-resistant substrate. The selected dielectric resonator has a resonant frequency fr = 2.4 GHz and dielectric constant εr = 9.8. Computer Simulation Technology (CST) Microwave Studio was used to perform the simulation and analysis. The gain of the proposed antenna is 1.508 dBi and the directivity is 2.121 dBi.
Keren Naomi Devnesh, V U Yuvadharseni, S Revathi, Rahul Krishnan, and S. Vanaja
IEEE
This paper describes the simple design of a dielectric resonator antenna for 2.4 GHz using a regular cubic resonator. Dielectric resonator antennas (DRAs) are used at microwave and millimeter frequencies and consist of materials having a high dielectric constant that have high gain and directivity. The resonator is placed upon a copper-grounded fire-resistant substrate. The selected dielectric resonator has a resonant frequency fr = 2.4 GHz and dielectric constant εr = 9.8. Computer Simulation Technology (CST) Microwave Studio was used to perform the simulation and analysis. The gain of the proposed antenna is 1.633 dBi and the directivity is 2.205 dBi.
Rahul Krishnan, R. Ganesan, K Baskaran, Annie Grace Vimala, John Kalloor, and A. SenthilKumar
Elsevier BV
Vanaja Selvaraj, Divya Baskaran, P.H. Rao, Poonguzhali Srinivasan, and Rahul Krishnan
Informa UK Limited
ABSTRACT This paper proposes a simple and computationally efficient algorithm for the detection and localization of early tumors (<5 mm) in the breast tissues. The feasibility of the proposed technique is demonstrated with three-dimensional EM simulators and validated with experimental results on a breast phantom using wideband patch antenna operating in 2.4–4.7 GHz band. The proposed method identifies the tumor location and the depth of the tumor. This is accomplished by employing a mean value approach and an efficient algorithm. Average value of the backscattered signal received by the antenna at different location is considered in the mean value technique. The depth of tumor is identified by Ground Penetrating Radar algorithm which employs the backscattered signals from the breast tissues. These data are converted to B-scan image which in turn gives the depth of the tumor. The results obtained in the experiment are in congruence with the simulated results. In the experimental analysis, the tumor location is identified when the size of the tumor is large owing to the low sensitivity of the antenna.
R. Santhana Krishnan, E. Golden Julie, Y. Harold Robinson, Raghvendra Kumar, Pham Huy Thong, and Le Hoang Son
Elsevier BV
J.Joselin Jeya Sheela, S. Vanaja, Rahul Krishnan, V Avinash., D. Aruna, and D. Harini
IEEE
In this paper, an ultra-wideband (UWB) antenna with highly directional property is developed for microwave breast imaging applications. Two different patch antennas are designed to obtain the required performance. The proposed two different novel designs of a square and circular patch antenna show a reflection coefficient less than -10dB over a frequency range of 1. 4GHz to 10 GHz. The gain of the square and circular patch antenna is 6. 06dB and 5. 5dB whereas the directivity of the square shape antenna and circular patch antenna is 8. 37dBi and 6. 96dBi. The important characteristics of these square and circular antenna schemes are the cautious engineering of the ground plane with etching a slot having a width of 2.25mm on the ground plane margin, which authorizes the wide bandwidth over the complete UWB range. By introducing the gap in between the ground and patch plane, lower frequency band of operation is attained. The proposed two different antennas shows directional radiation pattern, wide bandwidth and good gain which is enough for the microwave imaging application. The VSWR is less than 2 over the entire range of UWB band.
Rahul Krishnan, Vanaja Selvaraj, D. Sasirekha, K. Lalitha, K. Jayamani, and Rajasekhar Atla
IEEE
This paper consists of a compact polarization-independent dual-band pass Frequency Selective Surface (FSS) for smart phone safety application. The FSS structure is entrenched in FR-4 substrate, which acts as a band pass filter for a frequency of 2.4 GHz and 5 GHz. These two pass band frequencies are independently controlled by tuning the unit cell geometrical parameters. The unit cell shows a symmetrical shape to enable constant performance in both TE and TM mode. By considering different angles (0°- 60°) for the incidence of waves and the angular stability is verified. The proposed unit cell structure is developed with the help of CST microwave studio. The performance of the proposed FSS were validated with the help of simulated and measured results. In reflection mode analysis, the specific frequency is passed and the remaining frequencies received at the receiving end are attenuated near to 30 dB. The accurate results are obtained at 2.25 GHz and 4.77 GHz.
Vanaja Selvaraj, Poonguzhali Srinivasan, Divya Baskaran, and Rahul Krishnan
Inderscience Publishers
R. Santhana Krishnan, E. Golden Julie, Y. Harold Robinson, Le Hoang Son, Raghvendra Kumar, Mohamed Abdel-Basset, and Pham Huy Thong
Institute of Electrical and Electronics Engineers (IEEE)
Multicast routing protocols normally depend upon the standard establishment of a multicast tree that needs maintenance of state information by individual nodes. In the case of dynamic networks with burst traffic, between the bursts of data, a long period of silence is expected. The multicast state preservation appends a huge amount of transmission and memory overload. This is no longer suitable for any applications. Therefore, this paper proposes a stateless high power node multicasting method utilizing a group of sink node data, which are implanted in packet headers, to facilitate recipients to fix the finest technique to send data packets in the multicast traffic. In order to eliminate expensive state information of the neighbor table, the HPN multicast protocol utilizes the awareness of the exact positions of sensor nodes. This protocol will be preferably appropriate for multicasting in active networks. The simulation results confirm that HPN multicast affords elevated success rates and little delay exclusive of the trouble of state information.