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Author

Singaravelu Raghavan

Other affiliations: Techno India
Bio: Singaravelu Raghavan is an academic researcher from National Institute of Technology, Tiruchirappalli. The author has contributed to research in topics: Microstrip antenna & Monopole antenna. The author has an hindex of 19, co-authored 230 publications receiving 1572 citations. Previous affiliations of Singaravelu Raghavan include Techno India.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a triple-band antenna for the frequency bands 2.4, 3.5 and 5 GHz is proposed for the IEEE 802.11a/b/g and 802.16e standards.
Abstract: This paper presents a compact triple band antenna for the frequency bands 2.4, 3.5 and 5 GHz. These bands are assigned to the IEEE 802.11a/b/g and IEEE 802.16e standards. The resonant modes for WLAN, WiMAX bands are achieved by employing a rectangular slot and a metamaterial inspired split ring structure. The extraction procedure of negative permeability for the proposed split ring resonator is discussed in detail. Tunability between the WLAN and WiMAX standards is demonstrated by using a single PIN diode. The proposed antenna with a compact size of 27 mm × 25 mm is fabricated and tested. The triple band antenna yields a −10 dB impedance bandwidth of about 18.6%, 4.3% and 40.3% in 2.4, 3.5 and 5 GHz bands respectively. Stable radiation patterns with low cross polarization and high average antenna gain of 2.46 dBi are observed for the operating bands.

82 citations

Journal ArticleDOI
TL;DR: In this paper, a microstrip patch antenna with complementary split ring resonator (CSRR) loaded ground plane is proposed for gain improvement, which has good radiation pattern and very good gain of 5.93 dBi at resonant frequency.
Abstract: In this article, microstrip patch antenna with complementary split ring resonator (CSRR) loaded ground plane is proposed for gain improvement. Gain was improved by introducing CSRR slots on the ground plane. The proposed antenna is designed, fabricated, and tested. Measured results are in good agreement with simulation results. The proposed antenna has a size of 40 × 46 × 1.6 mm3. The measured impedance bandwidth is 100 MHz (return loss <−10 dB) from 2.4 to 2.5 GHz, which covers instruments, scientific and measurement (ISM) band applications. Omnidirectional radiation pattern obtained in H-plane and bidirectional radiation pattern obtained in E-plane. Parametric study of CSRR was done to obtain best results. The proposed antenna is simple, has good radiation pattern, and very good gain of 5.93 dBi at resonant frequency. Size reduction of 10% was also achieved and bandwidth is slightly greater than unloaded antenna. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:292–296, 2015

77 citations

Journal ArticleDOI
TL;DR: In this article, a low-profile antenna-triplexer is realized using a substrate integrated waveguide (SIW) technology for radio altimeter/WLAN/ISM band applications.
Abstract: A low-profile antenna-triplexer is realized using a substrate integrated waveguide (SIW) technology for radio altimeter/WLAN/ISM band applications. The antenna is composed of two SIW cavity resonators where a smaller cavity is nested inside the larger one. The larger cavity is excited by using two distinct microstrip feedlines, while the smaller one by a coax probe. The antenna produces three distinct resonances around 4.18, 5.2, and 5.8 GHz simultaneously employing one annular slot and two transverse slots. By exciting cavity modes (TE110/TE 120) and the patch mode (TM10) simultaneously, an average isolation of better than 23 dB is accomplished among three input ports. As compared to the conventional counterparts, the proposed geometry is simple to realize in a compact space. To validate the proposed idea, the design is experimentally tested, and the measured responses show a good agreement with the simulations. Moreover, the antenna shows a front-to-back ratio better than 19 dB and measured gain values of 6.56, 4.2, and 5.85 dBi at three resonances. The proposed design is compact, easy to fabricate, and capable to integrate with planar circuits.

59 citations

Journal ArticleDOI
TL;DR: In this article, a self-triplexing slot antenna using substrate integrated waveguide (SIW) technique is demonstrated for multiband communication systems, which operates at triple frequency bands (around 6.53, 7.65, and 9.09 GHz) simultaneously utilizing a slot inserted on the top of the SIW cavity and is excited by three separate microstrip lines.
Abstract: In this letter, a new design of self-triplexing slot antenna using substrate integrated waveguide (SIW) technique is demonstrated for multiband communication systems. The proposed antenna operates at triple frequency bands (around 6.53, 7.65, and 9.09 GHz) simultaneously utilizing a slot inserted on the top of the SIW cavity and is excited by three separate microstrip lines. By properly optimizing the antenna parameters, an isolation of better than 19 dB is realized between any two input ports, which helps to achieve self-triplexing property. The proposed triplexing antenna preserves simplicity, compactness, and a planar configuration that makes it suitable for highly integrated handheld devices. To demonstrate the significance of the proposed work, the antenna is prototyped, and experimental results show a close agreement with simulations. Moreover, the proposed antenna exhibits the measured gain of 3.1, 4.7, and 3.9 dBi at resonant frequencies with stable radiation patterns.

56 citations

Journal ArticleDOI
TL;DR: In this paper, a compact semi circular monopole antenna with complementary split ring resonance (CSRR) and two C-shaped slots is proposed for Global System for Mobile Communication (GSM), Worldwide Interoperability for Microwave Access (WiMAX) and C-band applications.
Abstract: This paper presents a compact semi circular monopole antenna loaded with Complementary Split Ring Resonator (CSRR) and two C-shaped slots is proposed for Global System for Mobile Communication (GSM), Worldwide Interoperability for Microwave Access (WiMAX) and C-band applications. The size of the proposed antenna is 20 × 20 × 0.5 mm 3 . The resonance frequency of WiMAX (3.73 GHz) is achieved by introducing CSRR slots on the ground plane. To realize multiband characteristics for GSM (1.77 GHz), WiMAX (2.6 GHz) and C-band (4.15 GHz), two C-shaped slots of quarter wavelength are introduced in radiating element. The extraction procedure of negative permittivity for the proposed CSRR is discussed in detail. The proposed antenna is fabricated and measured. Simulated and measured results are in good agreement. Omni directional radiation pattern is obtained in H-plane and bi directional radiation pattern is obtained in E-plane. Parametric study of CSRR and C-shaped slot are examined to obtain best results. The proposed antenna has significant advantages, including low profile, miniaturization ability, and good impedance matching.

48 citations


Cited by
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Journal ArticleDOI
TL;DR: An in-depth critical analysis is presented that aims to inspire and align the agendas of the two scientific groups in the field of small bowel diseases.
Abstract: Video capsule endoscopy (VCE) has revolutionized the diagnostic work-up in the field of small bowel diseases. Furthermore, VCE has the potential to become the leading screening technique for the entire gastrointestinal tract. Computational methods that can be implemented in software can enhance the diagnostic yield of VCE both in terms of efficiency and diagnostic accuracy. Since the appearance of the first capsule endoscope in clinical practice in 2001, information technology (IT) research groups have proposed a variety of such methods, including algorithms for detecting haemorrhage and lesions, reducing the reviewing time, localizing the capsule or lesion, assessing intestinal motility, enhancing the video quality and managing the data. Even though research is prolific (as measured by publication activity), the progress made during the past 5 years can only be considered as marginal with respect to clinically significant outcomes. One thing is clear-parallel pathways of medical and IT scientists exist, each publishing in their own area, but where do these research pathways meet? Could the proposed IT plans have any clinical effect and do clinicians really understand the limitations of VCE software? In this Review, we present an in-depth critical analysis that aims to inspire and align the agendas of the two scientific groups.

187 citations

Book
01 May 1989

101 citations