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ANN model of RF MEMS lateral SPDT switches for millimeter wave applications
(PubMed ID, 2012-07-16) Suganthi, S; Murugesan, K; Ragavan, S
his paper presents Artificial Neural Network (ANN) implementation for the Radio Frequency (RF) and Mechanical modeling of lateral RF Micro Electro Mechanical System (MEMS) series micro machined Single pole double through (SPDT) switch. We propose an efficient approach based on ANN for analyzing the losses in ON and OFF state of lateral RF MEMS series switch by calculating the S-parameters. The double beam structure has been analyzed in terms of its return, isolation and insertion losses with the variation of its passive circuit component values. The effect of design parameters has been analyzed and the lateral switch was realized with low insertion loss, high return and isolation losses. ANN model were trained with five different training algorithms namely Levenberg-Marquart (LM), Bayesian Regularization (BR), Quasi - Newton (QN), Scaled Conjugate Gradient (SCG) and Conjugate Gradient of Fletcher - Powell (CGF) to obtain better performance and fast convergence. The results from the neural model trained by Levenberg-Marquardt back propagation algorithm are highly agreed with the theoretical results available in the literature. The neural networks shows the better results with the highest correlation coefficient which measures the strength and direction of linear relation between two variables (actual and predicted values) (0.9998) along with lowest root mean square error (MSE) of (0.0039).
Coplanar waveguide-fed ultra-wideband planar antenna with WLAN-band rejection
(Sociedade Brasileira de Microondas e Optoeletronica (SBMO), 2013-08-27) Subbarao, A; Raghavan, S
A compact coplanar waveguide (CPW)-fed ultrawideband (UWB) antenna is proposed with band-notched characteristic. The antenna has compact size of 29 × 31 mm2. A novel wide polygon-slot is inserted on the antenna to obtain good impedance matching and wide bandwidth. A tapered radiating patch is placed inside the polygon-slot. An embedded C-slot in the radiating patch avoids potential interference from WLAN band. The antenna is fabricated and measured. The measured results confirm that the antenna has operating frequency band of 3.1-10.6 GHz with notched band of 5.1-5.9 GHz. The antenna has stable radiation patterns and consistent gain over operating band. The time domain group delay of antenna is with in 1 ns except in notched band, which indicates good linear phase response. The results indicate that the antenna is good for portable UWB systems.
Design and analysis of open complementary split ring resonators loaded monopole antenna for multiband operation
(Electromagnetics Academy, 2017-10-12) Daniel, Raphael Samson; Pandeeswari, Ramasamy; Raghavan, Singaravelu
This paper describes a compact triple-band monopole antenna based on Open Complementary Split Ring Resonators (OCSRRs) for Wireless Local Area Network (WLAN) and Worldwide interoperability Microwave Access (WiMAX) applications. The monopole antenna with engraved ground plane is used to cover WLAN frequencies (2.67 GHz and 5.47 GHz). The resonant frequency of WiMAX (3.43GHz) is achieved by introducing OCSRR in the monopole antenna. In order to achieve multiband and good impedance matching, OCSRRs are introduced in the rectangular monopole antenna. The prototype antenna is fabricated on an FR-4 substrate having dimension of 29.4 × 26 × 1.6mm3. Simulated and measured results are shown in good equivalence. The dipole radiation pattern is obtained in the elevation plane (E-plane), and omnidirectional radiation pattern is obtained in the azimuthal plane (H-plane). Parametric analysis of OCSRRs is studied to attain the best results. The proposed antenna has adequate advantages, including compact size, multiband, and impedance matching.
Design and analysis of open complementary split ring resonators loaded monopole antenna for multiband operation
(Electromagnetics Academy, 2017-10-12) Daniel, Raphael Samson; Pandeeswari, Ramasamy; Raghavan, Singaravelu
This paper describes a compact triple-band monopole antenna based on Open Complementary Split Ring Resonators (OCSRRs) for Wireless Local Area Network (WLAN) and Worldwide interoperability Microwave Access (WiMAX) applications. The monopole antenna with engraved ground plane is used to cover WLAN frequencies (2.67 GHz and 5.47 GHz). The resonant frequency of WiMAX (3.43GHz) is achieved by introducing OCSRR in the monopole antenna. In order to achieve multiband and good impedance matching, OCSRRs are introduced in the rectangular monopole antenna. The prototype antenna is fabricated on an FR-4 substrate having dimension of 29.4 × 26 × 1.6mm3. Simulated and measured results are shown in good equivalence. The dipole radiation pattern is obtained in the elevation plane (E-plane), and omnidirectional radiation pattern is obtained in the azimuthal plane (H-plane). Parametric analysis of OCSRRs is studied to attain the best results. The proposed antenna has adequate advantages, including compact size, multiband, and impedance matching.
Complimentary split ring resonator inspired meandered CPW-fed monopole antenna for multiband operation
(Electromagnetics Academy, 2017-12-01) Pandeeswari, Ramasamy
A novel design of Meandered Coplanar waveguide (CPW) fed CSRR loaded multiband antenna is presented in this paper. A compact triple-band antenna is designed by etching CSRR slots on the radiating element. The proposed antenna shows good performance at all resonant frequencies. The simulation results are discussed and compared with the measured ones. The effects of CSRR loading on the radiating element are explained. Parametric studies are carried out and explained in detail. The proposed antenna is fabricated and measured, and the results are compared with the simulated ones. CSRR permittivity characteristics are explained to validate the results. The proposed antenna can be used for C-band, Wireless Local Area Network (WLAN) and International Telecommunications Union (ITU) applications.
SRR and NBCSRR Inspired CPW Fed Triple Band Antenna with Modified Ground Plane
(Electromagnetics Academy, 2018-01-12) Pandeeswari, Ramasamy
In this paper, a novel CPW-fed triple band metamaterial inspired antenna with modified ground plane is presented. The metamaterial inspired structures such as split ring resonator (SRR) and non bianisotropic complementary split ring resonator (NBCSRR) are embeded in this antenna for triple band operation. The proposed antenna with a compact size of 25 × 31.7 × 1.6mm3 is fabricated and tested. The antenna with good radiation characteristics is suitable for WIMAX, C band and WLAN applications. The simulated and measured results are discussed and are in good agreement with each other.
SRR-loaded metamaterial-inspired electrically-small monopole antenna
(Electromagnetics Academy, 2018-01-25) Chaturvedi, Divya Send mail to Chaturvedi D.; Raghavan, Singaravelu
In this paper, a CPW-fed compact metamaterial-inspired monopole antenna is proposed for Industrial, Scientific and Medical radio band (ISM, 2.4–2.483 GHz). The proposed antenna consists of a T-shaped patch and a set of split ring resonators (SRRs). The miniaturization is attained after loading SRRs in proximity to the T-shaped radiator, which makes the antenna structure electrically small. The measured fractional bandwidth of the antenna is 4% (2.42–2.52 GHz), and its size is 0.22λo 0.098λo ×.013λo. In addition, the electrically equivalent circuit of the proposed antenna is modeled, and the resonant frequency is calculated by using an analytical approach. Also, the permeability plot of SRRs is extracted using Nicolson Ross weir method. The measured peak gain and radiation efficiency of the antenna are obtained as 1.76 dBi and 78.5%. The simulated results and measured results are found in a good agreement.
A compact non-bianisotropic complementary split ring resonator inspired microstrip triple band antenna
(Electromagnetics Academy, 2018-02-13) Pandeeswari, Ramasamy
A Compact Non-Bianisotropic Complementary Split Ring Resonator (NB-CSRR) based microstrip triple band antenna is presented in this paper. The antenna has a simple structure compared to other antennas for triple band operation. The antenna consists of a microstrip-fed NBCSRR loaded radiating element and partial ground plane. The designed antenna has a compact size of 29.4 mm × 26 mm × 1.6 mm. Two NBCSRR slots are etched on the radiating patch. Bottom NB-CSRR is used to generate new resonance, and top NB-CSRR is used to improve the return loss. The measured data show that the antenna covers the frequency ranges of 2.5 GHz–3.61 GHz, 4.06 GHz– 4.69 GHz, 4.80 GHz–6.07 GHz with impedance bandwidth of (< −10 dB) of 1.11 GHz, 0.63 GHz and 1.27 GHz. The results show that the antenna can cover WLAN and C band applications.
A triangular-shaped quarter-mode substrate integrated waveguide based antenna for WBAN applications
(Defense Scientific Information and Documentation Centre, 2018-03-13) Chaturvedi, Divya; Raghavan, S
In this study, a compact quarter-mode substrate integrated waveguide (QMSIW) based dual-band antenna is proposed for wireless body area network applications. A QMSIW resonator is realised by splitting the full-mode substrate integrated waveguide cavity along the perfect magnetic conductor walls. The proposed antenna preserves the fundamental mode TE1I5 and the third order mode TE.Q of the square SIW cavity. The proposed antenna is linearly polarised in the lower band at 2.45 GHz and circularly polarised in the higher frequency band at 5.8 GHz. The on-body performance of the antenna is validated on a piece of pork muscle tissue and it has been found to be stable with respect to surroundings. The proposed antenna covers the ISM bands 44 MHz (2.445 GHz-2.489 GHz) and 225 MHz (5.730 GHz-5~955 GHz) at 2.45 GHz and 5.8 GHz, respectively. The measured gain of the antenna on pork tissue is 1.87 dBi and 5.5 dBi at two bands. In addition, the specific absorption rate is obtained of 0.65 m\V g and 1.51 mW/g at two bands (it∗ = 2 mm), averaged over 1 g of muscle with lOOmW input power. Moreover, the simulated and experimental results demonstrate a good agreement. © 2018, DESIDOC.
Compact QMSIW based antennas for WLAN/WBAN applications
(Electromagnetics Academy, 2018-03-28) Chaturvedi, Divya; Raghavan, Singaravelu
In this paper, two compact planar substrate integrated waveguide (SIW) cavity-backed antennas are proposed for wireless local area network (WLAN) at 5.5GHz and wireless body area network (WBAN) at 5.8GHz. The miniaturization is achieved with the concept of quarter-modetopology, and the size of the cavity is reduced up to one-fourth of the circular SIW cavity. A L-shaped slot is etched on the top plane for miniaturization, and antenna-1 is realized which resonates at 5.5GHz. A metal strip has been added in the middle section of the slot, and antenna-2 is realized, which resonates at 5.8GHz. Both proposed antennas are tested in free space, while the performance of antenna-2 is investigated for on-body condition. In free space, the measured impedance bandwidths of the antenna are 160 MHz and 210MHz at 5.5 GHz and 5.8GHz, respectively. The radiation efficiency of the antenna is 89.4% in free space and 57% on phantom at 5.8GHz. Both measured and simulated results are observed, and they are in a good agreement.
Compact dual-band substrate integrated waveguide crossover with high isolation
(Electromagnetics Academy, 2019-03-22) Karthikeyan, Sholampettai Subramanian
—A compact dual-band substrate integrated waveguide (SIW) crossover with high isolation is proposed. Two identical slots are etched on the ground plane to achieve dual-band response and compact size. The passbands are generated below the cutoff frequency of the SIW due to the electric dipole behaviour of the slots. In-line ports are also employed to obtain good transmission and high isolation. To validate the concept, a dual-band crossover operating at 2.4 GHz and 5.4 GHz is designed, fabricated, and measured. The crossover size including in-line ports is 43.2 × 43.2mm2,equivalentto 0.43λg × 0.43λg,hereλg is the guided wavelength at the first operating frequency. The tested insertion loss and isolation at the two operating frequencies are smaller than 0.27 dB and greater than 40 dB, respectively.
Compact complementary folded triangle split ring resonator triband mobile handset planar antenna for voice and wi-fi applications
(Electromagnetics Academy, 2019-04-11) Rajalakshmi, P; Gunavathi, N
In this work, a Complementary Folded Triangle Split Ring Resonator (CFTSRR) loaded triband mobile handset planar antenna is presented. The proposed antenna consists of a dumbbellshaped radiating element and two CFTSRR metamaterial unit cells. The dumbbell-shaped radiating element resonates at 5GHz. The presence of CFTSRRs additionally offers two lower band resonance. The CFTSRR-1 and CFTSRR-2 exhibit negative permittivity at 1.8GHz and 2.4 GHz, respectively. The proposed antenna is designed to resonate at 1.8GHz (GSM1800 MHz), 2.4 GHz, and 5 GHz (IEEE802.11ax) for voice and Wi-Fi applications of the mobile handset, respectively. The proposed antenna demonstrates compactness up to 88.6% at 1.8GHz. The parametric studies are investigated to optimize the antenna in desired frequency bands by using Ansys HFSS19 software. The simulated and measured results are discussed. The measured result shows -10 dB reflection coefficient with bandwidth about 250 MHz (1.6GHz-1.85 GHz), 50MHz (2.375 GHz-2.425 GHz), and 225 MHz (4.925 GHz-5.15 GHz) which are 14.5%, 2%, and 5% respectively around their center frequencies. The measured maximum gain is approximately 1.7 dBi, 8 dBi, and 11.5 dBi for 1.8 GHz, 2.4GHz, and 5GHz, respectively.
Spatial and polarization angle estimation of mixed-targets in MIMO radar
(Electromagnetics Academy, 2019-06-20) Chintagunta, Srinivasarao; Ponnusamy, Palanisamy
This paper proposes an approach for estimating the spatial and polarization angles of mixed-targets in bistatic MIMO radar. Mixed-targets mean the combination of uncorrelated, partially correlated, and groups of coherent targets. The approach resolves rank deficiency of received signal covariance matrix and then exploits the ESPRIT-based method for estimating the angles of direction-of-departure (DOD) and direction-of-arrival (DOA). This paper also presents an analytical review and necessary conditions for resolving the rank deficiency under various scenarios of the MIMO radar. Simulation results show the effectiveness of the proposed approach.
Metamaterial inspired structure with offset-fed microstrip line for multi band operations
(Electromagnetics Academy, 2019-06-25) Murugeshwari, Balasubramanian; Daniel, Raphael Samson; Raghavan, Singaravelu
A miniaturized rectangle-shaped complementary split ring radiating element with an offset-fed microstrip line is reported for multiband operations. The fabricated antenna with a compact size of 19×19×1.6 mm3 is designed on an FR-4 substrate with loss tangent tan δ = 0.02 and dielectric constant (εr) of 4.4. Multiband and antenna miniaturization are achieved by a complementary split ring radiating element, and it produces an impedance bandwidth of 40 MHz resonance at 3.03 GHz, 40 MHz resonance at 3.66 GHz, and 1470 MHz resonance at 5.5 GHz. The passband behaviour of the complementary split ring radiating element is studied in detail for obtaining multiband abilities of the miniaturized antenna. The metamaterial property of the complementary split ring radiating element is analyzed, by which the negative permittivity (ε) existence and the new resonance frequency are confirmed. The fabricated antenna shows optimum performance at the measured radiation characteristics. © 2019, Electromagnetics Academy. All rights reserved
Direct localization of multiple noncircular sources with a moving nested array
(Institute of Electrical and Electronics Engineers Inc., 2019-07-18) Kumar, Gowri; Ponnusamy, Palanisamy; Amiri, Iraj Sadegh
This paper proposes a subspace data fusion (SDF)-based direct positioning determination (DPD) method for noncircular sources with a moving nested array (NA). The DPD algorithms using a uniform linear array (ULA) and coprime (CP) array are available in the existing literature. Sparse arrays have larger apertures than ULAs, which enhances degrees of freedom (DOFs). However, the existing sparse CP arrays have limited DOF and also have poor detecting ability. In this paper, the physical sensors of NA are rearranged to obtain a difference sum NA (DSNA) and second-order super NA (II-SNA). The rearranged NA sensors are seen to increase array aperture. The noncircular characteristics of the sources are also used to improve accuracy in positioning. To obtain high DOF in NA, DSNA, and II-SNA, the covariance matrices are vectorized. The coherency of the virtual array is resolved by applying the spatial smoothing technique. Finally, the SDF-based DPD is used to establish the cost function and the target is localized. The simulation results are provided for the NA, DSNA, and II-SNA and are compared with the existing CP array DPD algorithm. The results show that the proposed method shows signi-cant enhancement in localization accuracy. The Cramer-Rao lower bound (CRLB), complexity, and performance comparisons are also described in this paper.
Magnitude comparator realization using threshold logic
(Blue Eyes Intelligence Engineering and Sciences Publication, 2019-09) Soumya, R; Sureh Babu, V; Gopi, Varun P.
Threshold logic design can be regarded as an alternative method of traditional logic gate design. Threshold logic can be considered as the primary logic of brain. Neurons can be considered as threshold logic gates. Each neuron fires when its activation threshold is crossed. The basic idea behind threshold logic is threshold decision principle. Threshold decision principle checks whether the weighted sum of inputs crosses a threshold and accordingly output is defined. Several implementations for threshold logic were proposed. Resistive threshold logic is a new method for threshold logic implementation. In this paper, using the concept of resistive threshold logic, a magnitude comparator is realized. LTSpiceIV and Electric VLSI Design System are the simulation tools used in this work.
Polarization difference smoothing in bistatic MIMO radar
(Electromagnetics Academy, 2019-12-09) Subramaniam, Karthick; Ponnusamy, Palanisamy; Chintagunta, Srinivasarao
This paper investigates the joint direction of departure (DOD) and direction of arrival (DOA) estimation of coherent targets in bistatic multiple-input multiple-output (MIMO) radar under the presence of spatially correlated noise. Based on electromagnetic vector sensors at both transmitter and receiver of MIMO radar, a preprocessing method, namely polarization difference smoothing, is proposed to remove the coherence between targets and to suppress the spatially correlated noise. Then DODs and DOAs are estimated using the ESPRIT method. Further, this paper develops a simple approach for pair-matching between the estimated DODs and DOAs. Simulation results are compared with the receive polarization smoothing and transmit-receive polarization smoothing methods available in literature. Results show that the proposed approach improves the performance significantly.
A new green prospective of non-orthogonal multiple access (NOMA) for 5G
(MDPI AG, 2020-02-07) Basnayake, Vishaka; Jayakody, Dushantha Nalin K.; Sharma, Vishal; Sharma, Nikhil; Muthuchidambaranathan, P; Mabed, Hakim
Energy efficiency is a major concern in the emerging mobile cellular wireless networks since massive connectivity is to be expected with high energy requirements from the network operators. Non-orthogonal multiple access (NOMA) being the frontier multiple access scheme for 5G, there exists numerous research attempts on enhancing the energy efficiency of NOMA enabled wireless networks while maintaining its outstanding performance metrics such as high throughput, data rates and capacity maximized optimally. The concept of green NOMA is introduced in a generalized manner to identify the energy efficient NOMA schemes. These schemes will result in an optimal scenario in which the energy generated for communication is managed sustainably. Hence, the effect on the environment, economy, living beings, etc is minimized. The recent research developments are classified for a better understanding of areas which are lacking attention and needs further improvement. Also, the performance comparison of energy efficient, NOMA schemes against conventional NOMA is presented. Finally, challenges and emerging research trends, for energy efficient NOMA are discussed.
Automated Binary and Multiclass Classification of Diabetic Retinopathy Using Haralick and Multiresolution Features
(Institute of Electrical and Electronics Engineers Inc., 2020-03-10) Gayathri, S; Krishna, Adithya K.; Gopi, Varun P.; Palanisamy, P
Diabetic Retinopathy (DR) is considered as the complication of Diabetes Mellitus that damages the blood vessels in the retina. This is characterized as a serious vision-threatening problem in most of the diabetic subjects. Effective automatic classification of diabetic retinopathy is a challenging task in the medical field. The feature extraction plays an eminent role in the effective classification of disease. The proposed work focuses on the extraction of Haralick and Anisotropic Dual-Tree Complex Wavelet Transform (ADTCWT) features that can perform reliable DR classification from retinal fundus images. The Haralick features are based on second-order statistics and ADTCWT reliably extracts the directional features in images. The proposed work concentrates on both binary classification as well as multiclass classification of DR. The system is evaluated across various classifiers such as Support Vector Machine (SVM), Random Forest, Random Tree, J48 classifiers by giving input image features extracted from the MESSIDOR, KAGGLE and DIARETDB0 databases. The performances of the classifiers are analyzed by comparing specificity, precision, recall, False Positive Rate (FPR) and accuracy values for each classifier. The evaluation results show that by applying the proposed feature extraction method, Random Forest outperforms all the other classifiers with an average accuracy of 99.7% and 99.82% for binary and multiclass classification respectively.
Design of Miniaturized SIW Filter Loaded with Open-Loop Resonators and its Application to Diplexer
(Czech Technical University, 2020-09-01) Barik, Rusan Kumar; Cheng, Qingsha S.; Pradhan, Nrusingha Charan; Karthikeyan, Sholampettai Submaranian
This paper presents a novel design of miniaturized substrate-integrated waveguide (SIW) filter loaded with a pair of unit-cell resonators. Two identical open-loop resonators are connected face-to-face to form a unit-cell. A pair of unit-cells is engraved on the surface of the SIW to develop an evanescent-mode bandpass filter. The proposed unit-cells behave as an electric-dipole and produce a passband smaller than the waveguide frequency. This reduction in resonant frequency allows us to achieve size miniaturization. An equivalent electrical-circuit model is developed and investigate for characterization of passband and transmission-zero. This filter structure is then employed to develop a SIW planar diplexer. Two SIW filter structures loaded with unit-cells are excited with a T-shaped feed line to achieve lower and upper channels of the diplexer. To demonstrate the analysis, both SIW filter and diplexer loaded with open-loop resonators are implemented and fabricated. The proposed SIW filter and diplexer prototypes exhibit size miniaturization, low insertion-loss and high-selectivity due to evanescent-mode transmission and sub-wavelength resonators. The measurement responses are very similar to the simulation responses.

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