Ravi Gangwar - Profile on Academia.edu (original) (raw)
Papers by Ravi Gangwar
Present day heavy ion accelerators use bunched ion beams of sub-nanosecond time scale for beam ac... more Present day heavy ion accelerators use bunched ion beams of sub-nanosecond time scale for beam acceleration. In order to monitor its longitudinal profile, fast faraday Cups are employed. Owing to the advent of microstrip technology and its fabrication process, planar structures have become easier to fabricate. A novel design using the same is developed with a special provision for mounting edge launch connectors through a microstripline, followed by a microstrip to stripline transistion to again a microstrip structure in the beam interaction hole. The entire structure is a 50 Ω is bidirectional. An experimental study on via placement around central strip has also been conducted to not only ensure the field containment around the strip but also for bandwidth enhancement. To measure ion beam currents from 10-100 nA and a bunch width of 1ns, device has been beam interaction hole of around 10mm. 3 dB bandwidth is measured >6 GHz with a rise time of ~60 ps. The devices are also provid...
Experimental investigation on probe feed equilateral triangular dielectric resonator antenna for 5.8 GHz ISM band (IEEE 802.11)
In this paper design and development of triangular dielectric resonator antenna (TDRA) has been i... more In this paper design and development of triangular dielectric resonator antenna (TDRA) has been investigated. The coaxial probe feed at the center of the ground plane has been used for excitation of the TDRA. For the fabrication 50 Ω coaxial probe has been fitted at the centre of ground plane. The input characteristics of the proposed antenna have been extracted through Ansoft HFSS simulation software, which are compared with experimental results. Also, the radiation characteristics of the proposed TDRA has been found through Ansoft HFSS simulation software and compared with experimental results. The simulated results have been in good agreement with experimental results. The near field distribution has been observed at resonant frequency 5.8 GHz. It is apparent from near field analysis that the coaxial probe excites TM10-1 dominant mode fields in the antenna elements. The proposed antenna provides nearly 10.34% bandwidth (S11| < −10 dB) at a resonant frequency of 5.8 GHz with 6....
Association of Meloidogyne incognita and Rhizoctonia bataticola in chickpea
Wideband MIMO hybrid cylindrical dielectric resonator antenna with improved diversity performance
2017 IEEE Conference on Antenna Measurements & Applications (CAMA), 2017
In this article, a wideband hybrid multiple input multiple output (MIMO) cylindrical dielectric r... more In this article, a wideband hybrid multiple input multiple output (MIMO) cylindrical dielectric resonator antenna (CDRA) is studied. The wideband isolation is achieved with the help of novel circular ring shaped defected ground structure. The proposed MIMO antenna operates in the frequency range 3.7GHz-7.25GHz. Isolation of proposed MIMO antenna (S12) is less than −17dB over the entire operating band. The proposed antenna is found suitable for WLAN and WiMAX applications.
Conceptual design approach of wideband fractal dielectric resonator antenna
IET Microwaves, Antennas & Propagation, 2020
This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindr... more This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindrical dielectric resonator antenna. CSFG provides wider bandwidth by the combination of two important concepts: (i) reduction in volume to the surface area of the complete radiating structure, which in turn reduces the Q-factor; (ii) generation of two radiating modes inside the radiating structure HEM 11δ and TM 01δ . The prototype of the proposed antenna is fabricated for verifying the simulated results. Measured reflection coefficient (| S 11 |) shows that the proposed antenna structure operates over the frequency range 2.2–3.5 GHz with the fractional bandwidth of 45.61%. Diversified radiation pattern, i.e. monopole (due to TM 01δ mode) and broadside (due to HEM 11δ mode) is also an important feature of the proposed antenna structure. The antenna design is relevant for WLAN (2.5 GHz) and WiMAX (3.3 GHz) applications.
Polarization independent triple band ultrathin conformal metamaterial absorber for C- and X-frequency bands
AEU - International Journal of Electronics and Communications, 2021
Abstract A triple-band polarization-independent conformal absorber for C- and X-frequency bands h... more Abstract A triple-band polarization-independent conformal absorber for C- and X-frequency bands have been presented. The designed absorber comprises a Jerusalem cross resonator at the center, surrounded by a quarter part of a square rings resonator with different sizes at each corner on a metal grounded dielectric substrate. The unit cell size is 0.23λo× 0.23λo and thickness of λo/153 at frequency 6.16 GHz. The absorption peaks were obtained at frequencies 6.16 GHz, 9.22 GHz, and 11.6 GHz with absorptivity 95%, 96 %, and 97%, respectively. It exhibited full wave at half maximum (FWHM) bandwidths of 160 MHz bands (6.04 GHz – 6.20 GHz, 240 MHz (9.09 GHz – 9.33 GHz), and 260 MHz (11.57 GHz -11.83 GHz), respectively. The designed absorber is shown four-fold symmetry, which makes it polarization independent. Normalized impedance and surface current distributions for all three absorption frequencies are analyzed for understanding the absorption phenomenon. The designed absorber has been tested for the curved surfaces with different central angles to show its conformal behavior, and it is perceived that measured results and simulated results have good agreement between them.
Microwave and Optical Technology Letters, 2018
In this article, a dual-sense circularly polarized (CP) hybrid antenna is reported. The proposed ... more In this article, a dual-sense circularly polarized (CP) hybrid antenna is reported. The proposed hybrid antenna comprises of an asymmetrical square ring-shaped printed line and a rectangular dielectric resonator (RDR). The asymmetricity present in the square ring is responsible for creating CP radiation with the opposite sense characteristics in the proposed antenna. Also, modified printed ring is used to excite TE 111 mode in the loaded RDR. This loading enhances the overall impedance bandwidth of the proposed antenna. For practical verification, a prototype of the proposed antenna is fabricated and tested. The measured outcomes indicate a close concurrence with the simulated outcomes. The proposed antenna works over the frequency range 3.28 GHz-5.78 GHz with a fractional bandwidth of 55.18%. Dual CP wave with dual-sense characteristics (Axial Ratio < 3 dB) are created in the frequency range 3.81-4.28 GHz and 4.98-5.28 GHz respectively. These responses make the proposed antenna suitable for WLAN and WiMAX applications.
Broadband circularly polarized dipole look-like F-shaped antenna with symmetrically inverted F-shaped modified ground plane
Microwave and Optical Technology Letters, 2018
AEU - International Journal of Electronics and Communications, 2018
This article inspects partially segmented circular monopole with elliptical slot for super wideba... more This article inspects partially segmented circular monopole with elliptical slot for super wideband applications. Two significant characteristics of proposed antenna design are: (i) partially segmented circular monopole, notch loaded elliptical ground plane along with tapered microstrip line provides super wide bandwidth; (ii) elliptical slot in between the partially segmented circular monopole reduces the lower operating frequency (1.07 GHz to 0.96 GHz), which in turn enhance the bandwidth dimension ratio (BDR). For verifying the simulated outcomes, antenna prototype is practically constructed and measured. The proposed antenna design attains frequency range from 0.96 GHz to 10.9 GHz (VSWR < 2) with bandwidth ratio of 11.35:1 and percentage bandwidth of 167.22 %. Bandwidth dimension ratio of proposed radiator is 6975.22. Frequency as well as time domain analysis of proposed radiator approves its applicability for super wideband wireless applications.
IEEE Antennas and Wireless Propagation Letters, 2019
This work presents a novel partial reflector surface (PRS) structure to improve the isolation and... more This work presents a novel partial reflector surface (PRS) structure to improve the isolation and correlation coefficient values between cylindrical dielectric resonator antennas (cDRAs) for multiband multiple-input-multiple-output (MIMO) applications. To achieve multiband characteristics, three different groups of cDRA are proposed to cover 5.2 GHz, 5.5 GHz and 5.8 GHz bands, respectively. Each group has two cDRAs. So, three groups (i.e six cDRA) are placed at the top of the substrate and each cDRA is excited using a co-planer waveguide (CPW) fed conformal strip-line. To achieve improved isolation, three different phase gradient frequency selective surfaces (FSS) are designed which operate at 5.2 GHz, 5.5 GHz and 5.8 GHz bands, respectively. This phase gradient FSS is utilized as a superstrate above each group of DR elements. As a result, two different far-field patterns are achieved from each group of antenna elements which deliver improved isolation as well as low field correlation. This exclusive technique offers more than 12 dB of enhancement in isolation values and more than 70% improvement in envelope correlation coefficient (ECC) values, thus guaranteeing improved MIMO performance.
Microwave and Optical Technology Letters, 2018
bandwidth of the proposed antenna at the 28-GHz (i.e., 27.9-33.2 GHz) and 37-39 GHz (i.e., 34-39.... more bandwidth of the proposed antenna at the 28-GHz (i.e., 27.9-33.2 GHz) and 37-39 GHz (i.e., 34-39.1 GHz) which covers the FCC-allocated 5G bands. Parametric study has been carried out in order to analyze the frequency tuning parameters of the two resonating bands. This thorough MMW study suggests that L s controls the resonant frequency of band I, while band II can be tuned by changing L p . Figure ,B presents the parametric analysis carried out in simulations to illustrate the mentioned scenarios. The co-and crosspolarized far-field radiation patterns are shown in Figure at three frequencies, which depict a close match between simulations and measurements. The main beam in band I is along the boresight direction and tilted toward end-fire direction at an angle of 308. In band II, the maximum radiation is along the end-fire direction in 36-38 GHz with grating lobes, and exhibits a response similar to a leaky-wave antenna (LWA). Table provides the realized gain at the distinct frequencies of the operating range. Reasonable gain profile has been achieved over a wide operating range of K a -band. This investigation has thoroughly undertaken a novel approach to develop a multiband MMW element based on a proposed enhanced Franklin array model, for the potential employment in the 5G cellular networks. The standard theory of Franklin antenna is diversified by designing the geometrical modifications, in which the conventional nonradiating phasing stub of k/2 length has been transformed into the radiating stub of k/3 length. The antenna is designed to operate in the FCC-approved 5G bands, and offers high-gain profile and smaller form factor suitable for compact integration. Parametric study based on the radiating lengths has provided the ability to tune the frequency of any operating band, which effectively adds another degree of freedom into the systematic design framework. The multiband enhanced Franklin antenna offers distinguishing performance attributes, as required by the advanced paradigm shift which is currently undergoing for the K a -band 5G-centric communication architectures.
IEEE Antennas and Propagation Magazine, 2018
IETE Technical Review, 2019
In this communication, a dual-sense dual-polarized hybrid rectangular dielectric resonator antenn... more In this communication, a dual-sense dual-polarized hybrid rectangular dielectric resonator antenna (RDRA) is explored. Two leading aims of the present article include: (i) to obtain dualpolarization characteristics, i.e., the combination of linear and circular polarizations; (ii) to achieve quad-band features by using the concept of hybrid antenna. Modified printed line is used to excite dual radiating modes in RDRA, i.e., TE x δ11 and TE y 1δ1 . In order to authenticate the proposed radiator, archetype of the proposed antenna is fabricated and tested. Good accord is established between measured and simulated outcomes. The proposed radiator is operated over four different frequency bands, i.e., 1.81 GHz-2.06 GHz, 2.37 and Right Hand Circularly Polarized (RHCP) waves are obtained form 4.1-4.39 GHz and 4.78-5.2 GHz respectively. All these properties of the proposed radiator make it appropriate for 3G/WLAN/WiMAX applications. In recent era of wireless communication, it is required to have an antenna with low profile, light weight, high gain characteristics. In order to fulfill all these requirements, we have two different types of antennas: microstrip antenna and dielectric resonator antenna. Although microstrip antenna is able to fulfill all these requirements, it suffers from high metallic losses and low gain . To overcome this drawback, dielectric resonator antenna comes into the picture with high gain and high radiation efficiency. There are three basic shapes available in dielectric resonator antenna: hemispherical, cylindrical and rectangular ones. Out of the three, rectangular shape is widely used because it has two degrees of freedom . Two important antenna characteristics are required by the modern wireless communication, i.e., circular/dual-polarization characteristics and multiband characteristics. These radiators have a lot of advantages, such as capability to operate multiple operating bands, reducing multipath fading, and orientation insensitive. In open literature, there are three important methods available to create multiband features in dielectric resonator antenna, i.e., (i) grouping of DRA with other radiating elements, i.e., hybrid structure ; (ii) grouping of DRA with resonating element which is not directly connected to feeding structure ; (iii) multiple mode excitation in DRA . Similarly, some of the research works have also been done in the area of dual-polarized/circularly polarized DRAs such as hybrid Z-shaped CDRA, aperture coupled RDRA, probefed CDRA and chamfered DRA, and rectangular DRA with square shaped slot . In this article, a hybrid rectangular dielectric resonator antenna is presented. Square ring shaped monopole is used to originate two different frequency bands at 1.95 GHz and 5.09 GHz. An inverted Lshaped printed line is used to create orthogonal modes in RDRA, i.e., T E x δ11 and TE y 1δ1 and generates
Probe feed Multi-element Multi-segment Triangular Dielectric Resonator Antenna with RCS Analysis
Journal of Circuits, Systems and Computers, 2018
The aim of the paper is to propose a design and analysis of multi-element multi-segment triangula... more The aim of the paper is to propose a design and analysis of multi-element multi-segment triangular dielectric resonator antenna (MEMS TDRA) with Radar Cross-Section (RCS). The proposed antenna has been excited through coaxial probe feed. The coaxial probe feed excites TM[Formula: see text] dominant mode fields within the TDR elements. A general guideline for wide bandwidth and high gain has been prepared for designing of MEMS TDRA. The model of the proposed MEMS TDRA has been studied through simulation (Ansoft HFSS software) and fabricated for measurement. The simulated antenna performance has good agreement with the measured one. The proposed MEMS TDRA performance has been compared with some similar type of previously published structure and found wider bandwidth and higher gain. The proposed MEMS TDRA provides monopole-like radiation pattern with nearly 39% bandwidth ([Formula: see text] dB). The average gain of 6.0 dBi has been found over the entire bandwidth. The RCS analysis ha...
Dielectric resonator‐based four‐element eight‐port MIMO antenna with multi‐directional pattern diversity
IET Microwaves, Antennas & Propagation, 2018
This work presents a four-element, eight-port cylindrical dielectric resonator antenna (cDRA) wit... more This work presents a four-element, eight-port cylindrical dielectric resonator antenna (cDRA) with multi-directional pattern diversity for wireless access point applications. Initially, a dielectric resonator is fed by two different feeding techniques to create two simultaneous orthogonal patterns. This primary radiator is combined with similar radiators in a cross-configuration to obtain an eight-port multiple-input-multiple-output (MIMO) antenna system. The antenna elements are placed in such a way that each radiator of the proposed antenna can radiate in a different direction so that the field correlation between the antenna elements is minimum. The proposed diversity antenna consists of four antenna elements and eight polarised ports. Isolation between the ports is improved by generating orthogonal modes in each cDRA and exciting each cDRA to radiate in a different direction. The similarity in simulated and measured results confirm that the proposed eight-port diversity antenna is useful for the frequency ranges between 5.6 and 5.9 GHz for wireless local area network (WLAN) applications.
International Journal of RF and Microwave Computer-Aided Engineering, 2018
This communication explains the designing of two-port based hybrid radiator for multiple-input-mu... more This communication explains the designing of two-port based hybrid radiator for multiple-input-multiple-output (MIMO) applications. Hybrid radiator includes U-shaped printed line and ring dielectric resonator antenna (ri-DRA). Wideband characteristics have been achieved by exciting both the U-shaped printed line along with ri-DRA. The U-shaped metallic line acts as a magnetic dipole and helps to excite fundamental hybrid mode (HE 11δ ) in the ri-DRA. Dual L-shaped and a rectangular defect have been created in ground plane for achieving wideband isolation over the working frequency band. Optimized Scattering parameters and far-field results are verified by fabricating and testing of antenna prototype. Experimental outcomes confirm that the proposed MIMO antenna gives wider impedance bandwidth (80%), improved port isolation (better than 18 dB), stable gain (~4 dB), and radiation pattern. Various MIMO performance factors are analyzed and instituted in the tolerable boundaries.
Progress In Electromagnetics Research C, 2016
In this article, a dual-polarized hybrid cylindrical dielectric resonator antenna (CDRA) is studi... more In this article, a dual-polarized hybrid cylindrical dielectric resonator antenna (CDRA) is studied. A ring-shaped patch along with an inverted L-strip is used to excite two different hybrid modes (HE 11δ and HE 12δ-like mode) in CDRA. HE 12δ mode in CDRA is very advantageous in terms of gain and radiation characteristics. The proposed antenna design shows triple-band characteristics, i.e., 1.88-2.06 GHz, 2.29-2.58 GHz and 2.9-3.93 GHz with the fractional bandwidth of 9.13%, 11.9% and 30.16%, respectively. Due to inverted L-strip, it shows circular polarization characteristics within the frequency range 3.3-3.55 GHz (AR < 3 dB). The simulated results are practically verified by using archetype of proposed antenna structure. The proposed antenna design is applicable to WLAN (2.4 GHz) and WiMAX (2.5/3.5 GHz) applications.
International Journal of RF and Microwave Computer-Aided Engineering, 2017
This communication investigates composite cylindrical dielectric resonator antenna (CDRA) for var... more This communication investigates composite cylindrical dielectric resonator antenna (CDRA) for various wireless applications. Three important features of proposed antenna design are (i) realization of two different hybrid modes, that is, HEM 11d and HEM 12d mode in CDRA with the help of modified annular ring printed line (work as both magnetic dipole and electric dipole), both the hybrid modes support broadside radiation characteristics (ii) suppression of HEM 21d mode, in order to reduce the cross-polarization level in H-plane of other hybrid modes (HEM 11d and HEM 12d mode) by an amount of 8-10 dB (iii) creation of triple-band attribute using the concept of composite antenna. The proposed antenna design has been fabricated and practically tested. Simulated outcomes show good agreement with measured outcomes. It works in three frequency bands, that is, 2.25-2.79 GHz, 3.1-4.0 GHz, and 5.05-5.6 GHz. The designed antenna structure is appropriate for WLAN and WiMAX applications.
Two elements dual segment cylindrical dielectric resonator antenna array with annular shaped microstrip feed
2016 Twenty Second National Conference on Communication (NCC), 2016
In this paper, a dual segment two element wideband cylindrical dielectric resonator antenna array... more In this paper, a dual segment two element wideband cylindrical dielectric resonator antenna array with annular shaped corporate feed network is presented. To enhance impedance bandwidth, multisegmentation concept with shifted center has been pragmatic. Annular shaped microstrip parallel feed with quarter wave transformer etched on a single side of the copper grounded substrate (εr=4.4) is used to excite the dielectric resonator antenna. With this arrangement, approximately 46.8 % impedance bandwidth is achieved for the proposed cylindrical DRA array. The proposed antenna array gives the appreciable gain and better radiation characteristics at resonant frequencies. To validate the proposed design, a prototype of the proposed antenna array is fabricated, according to the optimized dimensions. Simulation is performed using Ansys HFSS simulation software and a close agreement between simulation and measured results has been observed.
International Journal of Microwave and Wireless Technologies, 2016
A probe feed wideband multi-element dual segments quarter cylindrical dielectric resonator antenn... more A probe feed wideband multi-element dual segments quarter cylindrical dielectric resonator antenna (q-CDRA) in composite forms have been proposed. The q-CDRA has been introduced by splitting CDRA into four uniform quarters and multi-segmentation approach has been castoff for further improvement in bandwidth of q-CDRA. The dual segments q-CDRA has been designed and analyzed using theoretical analysis and Ansoft HFSS simulation software. Further the dual segment multi-element q-CDRAs in composite form have been designed. A coaxial probe has been placed at the center of the ground plane for the excitation of proposed multi-element and multi-segmented composite form of q-CDRA, which excite TM01δ mode in the proposed antenna. The input characteristics and radiation patterns of the proposed composite antennas have been studied and their results are compared with corresponding experimental results. Prototype of single, two, and four elements dual-segment composite q-CDRAs have been fabrica...
Present day heavy ion accelerators use bunched ion beams of sub-nanosecond time scale for beam ac... more Present day heavy ion accelerators use bunched ion beams of sub-nanosecond time scale for beam acceleration. In order to monitor its longitudinal profile, fast faraday Cups are employed. Owing to the advent of microstrip technology and its fabrication process, planar structures have become easier to fabricate. A novel design using the same is developed with a special provision for mounting edge launch connectors through a microstripline, followed by a microstrip to stripline transistion to again a microstrip structure in the beam interaction hole. The entire structure is a 50 Ω is bidirectional. An experimental study on via placement around central strip has also been conducted to not only ensure the field containment around the strip but also for bandwidth enhancement. To measure ion beam currents from 10-100 nA and a bunch width of 1ns, device has been beam interaction hole of around 10mm. 3 dB bandwidth is measured >6 GHz with a rise time of ~60 ps. The devices are also provid...
Experimental investigation on probe feed equilateral triangular dielectric resonator antenna for 5.8 GHz ISM band (IEEE 802.11)
In this paper design and development of triangular dielectric resonator antenna (TDRA) has been i... more In this paper design and development of triangular dielectric resonator antenna (TDRA) has been investigated. The coaxial probe feed at the center of the ground plane has been used for excitation of the TDRA. For the fabrication 50 Ω coaxial probe has been fitted at the centre of ground plane. The input characteristics of the proposed antenna have been extracted through Ansoft HFSS simulation software, which are compared with experimental results. Also, the radiation characteristics of the proposed TDRA has been found through Ansoft HFSS simulation software and compared with experimental results. The simulated results have been in good agreement with experimental results. The near field distribution has been observed at resonant frequency 5.8 GHz. It is apparent from near field analysis that the coaxial probe excites TM10-1 dominant mode fields in the antenna elements. The proposed antenna provides nearly 10.34% bandwidth (S11| < −10 dB) at a resonant frequency of 5.8 GHz with 6....
Association of Meloidogyne incognita and Rhizoctonia bataticola in chickpea
Wideband MIMO hybrid cylindrical dielectric resonator antenna with improved diversity performance
2017 IEEE Conference on Antenna Measurements & Applications (CAMA), 2017
In this article, a wideband hybrid multiple input multiple output (MIMO) cylindrical dielectric r... more In this article, a wideband hybrid multiple input multiple output (MIMO) cylindrical dielectric resonator antenna (CDRA) is studied. The wideband isolation is achieved with the help of novel circular ring shaped defected ground structure. The proposed MIMO antenna operates in the frequency range 3.7GHz-7.25GHz. Isolation of proposed MIMO antenna (S12) is less than −17dB over the entire operating band. The proposed antenna is found suitable for WLAN and WiMAX applications.
Conceptual design approach of wideband fractal dielectric resonator antenna
IET Microwaves, Antennas & Propagation, 2020
This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindr... more This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindrical dielectric resonator antenna. CSFG provides wider bandwidth by the combination of two important concepts: (i) reduction in volume to the surface area of the complete radiating structure, which in turn reduces the Q-factor; (ii) generation of two radiating modes inside the radiating structure HEM 11δ and TM 01δ . The prototype of the proposed antenna is fabricated for verifying the simulated results. Measured reflection coefficient (| S 11 |) shows that the proposed antenna structure operates over the frequency range 2.2–3.5 GHz with the fractional bandwidth of 45.61%. Diversified radiation pattern, i.e. monopole (due to TM 01δ mode) and broadside (due to HEM 11δ mode) is also an important feature of the proposed antenna structure. The antenna design is relevant for WLAN (2.5 GHz) and WiMAX (3.3 GHz) applications.
Polarization independent triple band ultrathin conformal metamaterial absorber for C- and X-frequency bands
AEU - International Journal of Electronics and Communications, 2021
Abstract A triple-band polarization-independent conformal absorber for C- and X-frequency bands h... more Abstract A triple-band polarization-independent conformal absorber for C- and X-frequency bands have been presented. The designed absorber comprises a Jerusalem cross resonator at the center, surrounded by a quarter part of a square rings resonator with different sizes at each corner on a metal grounded dielectric substrate. The unit cell size is 0.23λo× 0.23λo and thickness of λo/153 at frequency 6.16 GHz. The absorption peaks were obtained at frequencies 6.16 GHz, 9.22 GHz, and 11.6 GHz with absorptivity 95%, 96 %, and 97%, respectively. It exhibited full wave at half maximum (FWHM) bandwidths of 160 MHz bands (6.04 GHz – 6.20 GHz, 240 MHz (9.09 GHz – 9.33 GHz), and 260 MHz (11.57 GHz -11.83 GHz), respectively. The designed absorber is shown four-fold symmetry, which makes it polarization independent. Normalized impedance and surface current distributions for all three absorption frequencies are analyzed for understanding the absorption phenomenon. The designed absorber has been tested for the curved surfaces with different central angles to show its conformal behavior, and it is perceived that measured results and simulated results have good agreement between them.
Microwave and Optical Technology Letters, 2018
In this article, a dual-sense circularly polarized (CP) hybrid antenna is reported. The proposed ... more In this article, a dual-sense circularly polarized (CP) hybrid antenna is reported. The proposed hybrid antenna comprises of an asymmetrical square ring-shaped printed line and a rectangular dielectric resonator (RDR). The asymmetricity present in the square ring is responsible for creating CP radiation with the opposite sense characteristics in the proposed antenna. Also, modified printed ring is used to excite TE 111 mode in the loaded RDR. This loading enhances the overall impedance bandwidth of the proposed antenna. For practical verification, a prototype of the proposed antenna is fabricated and tested. The measured outcomes indicate a close concurrence with the simulated outcomes. The proposed antenna works over the frequency range 3.28 GHz-5.78 GHz with a fractional bandwidth of 55.18%. Dual CP wave with dual-sense characteristics (Axial Ratio < 3 dB) are created in the frequency range 3.81-4.28 GHz and 4.98-5.28 GHz respectively. These responses make the proposed antenna suitable for WLAN and WiMAX applications.
Broadband circularly polarized dipole look-like F-shaped antenna with symmetrically inverted F-shaped modified ground plane
Microwave and Optical Technology Letters, 2018
AEU - International Journal of Electronics and Communications, 2018
This article inspects partially segmented circular monopole with elliptical slot for super wideba... more This article inspects partially segmented circular monopole with elliptical slot for super wideband applications. Two significant characteristics of proposed antenna design are: (i) partially segmented circular monopole, notch loaded elliptical ground plane along with tapered microstrip line provides super wide bandwidth; (ii) elliptical slot in between the partially segmented circular monopole reduces the lower operating frequency (1.07 GHz to 0.96 GHz), which in turn enhance the bandwidth dimension ratio (BDR). For verifying the simulated outcomes, antenna prototype is practically constructed and measured. The proposed antenna design attains frequency range from 0.96 GHz to 10.9 GHz (VSWR < 2) with bandwidth ratio of 11.35:1 and percentage bandwidth of 167.22 %. Bandwidth dimension ratio of proposed radiator is 6975.22. Frequency as well as time domain analysis of proposed radiator approves its applicability for super wideband wireless applications.
IEEE Antennas and Wireless Propagation Letters, 2019
This work presents a novel partial reflector surface (PRS) structure to improve the isolation and... more This work presents a novel partial reflector surface (PRS) structure to improve the isolation and correlation coefficient values between cylindrical dielectric resonator antennas (cDRAs) for multiband multiple-input-multiple-output (MIMO) applications. To achieve multiband characteristics, three different groups of cDRA are proposed to cover 5.2 GHz, 5.5 GHz and 5.8 GHz bands, respectively. Each group has two cDRAs. So, three groups (i.e six cDRA) are placed at the top of the substrate and each cDRA is excited using a co-planer waveguide (CPW) fed conformal strip-line. To achieve improved isolation, three different phase gradient frequency selective surfaces (FSS) are designed which operate at 5.2 GHz, 5.5 GHz and 5.8 GHz bands, respectively. This phase gradient FSS is utilized as a superstrate above each group of DR elements. As a result, two different far-field patterns are achieved from each group of antenna elements which deliver improved isolation as well as low field correlation. This exclusive technique offers more than 12 dB of enhancement in isolation values and more than 70% improvement in envelope correlation coefficient (ECC) values, thus guaranteeing improved MIMO performance.
Microwave and Optical Technology Letters, 2018
bandwidth of the proposed antenna at the 28-GHz (i.e., 27.9-33.2 GHz) and 37-39 GHz (i.e., 34-39.... more bandwidth of the proposed antenna at the 28-GHz (i.e., 27.9-33.2 GHz) and 37-39 GHz (i.e., 34-39.1 GHz) which covers the FCC-allocated 5G bands. Parametric study has been carried out in order to analyze the frequency tuning parameters of the two resonating bands. This thorough MMW study suggests that L s controls the resonant frequency of band I, while band II can be tuned by changing L p . Figure ,B presents the parametric analysis carried out in simulations to illustrate the mentioned scenarios. The co-and crosspolarized far-field radiation patterns are shown in Figure at three frequencies, which depict a close match between simulations and measurements. The main beam in band I is along the boresight direction and tilted toward end-fire direction at an angle of 308. In band II, the maximum radiation is along the end-fire direction in 36-38 GHz with grating lobes, and exhibits a response similar to a leaky-wave antenna (LWA). Table provides the realized gain at the distinct frequencies of the operating range. Reasonable gain profile has been achieved over a wide operating range of K a -band. This investigation has thoroughly undertaken a novel approach to develop a multiband MMW element based on a proposed enhanced Franklin array model, for the potential employment in the 5G cellular networks. The standard theory of Franklin antenna is diversified by designing the geometrical modifications, in which the conventional nonradiating phasing stub of k/2 length has been transformed into the radiating stub of k/3 length. The antenna is designed to operate in the FCC-approved 5G bands, and offers high-gain profile and smaller form factor suitable for compact integration. Parametric study based on the radiating lengths has provided the ability to tune the frequency of any operating band, which effectively adds another degree of freedom into the systematic design framework. The multiband enhanced Franklin antenna offers distinguishing performance attributes, as required by the advanced paradigm shift which is currently undergoing for the K a -band 5G-centric communication architectures.
IEEE Antennas and Propagation Magazine, 2018
IETE Technical Review, 2019
In this communication, a dual-sense dual-polarized hybrid rectangular dielectric resonator antenn... more In this communication, a dual-sense dual-polarized hybrid rectangular dielectric resonator antenna (RDRA) is explored. Two leading aims of the present article include: (i) to obtain dualpolarization characteristics, i.e., the combination of linear and circular polarizations; (ii) to achieve quad-band features by using the concept of hybrid antenna. Modified printed line is used to excite dual radiating modes in RDRA, i.e., TE x δ11 and TE y 1δ1 . In order to authenticate the proposed radiator, archetype of the proposed antenna is fabricated and tested. Good accord is established between measured and simulated outcomes. The proposed radiator is operated over four different frequency bands, i.e., 1.81 GHz-2.06 GHz, 2.37 and Right Hand Circularly Polarized (RHCP) waves are obtained form 4.1-4.39 GHz and 4.78-5.2 GHz respectively. All these properties of the proposed radiator make it appropriate for 3G/WLAN/WiMAX applications. In recent era of wireless communication, it is required to have an antenna with low profile, light weight, high gain characteristics. In order to fulfill all these requirements, we have two different types of antennas: microstrip antenna and dielectric resonator antenna. Although microstrip antenna is able to fulfill all these requirements, it suffers from high metallic losses and low gain . To overcome this drawback, dielectric resonator antenna comes into the picture with high gain and high radiation efficiency. There are three basic shapes available in dielectric resonator antenna: hemispherical, cylindrical and rectangular ones. Out of the three, rectangular shape is widely used because it has two degrees of freedom . Two important antenna characteristics are required by the modern wireless communication, i.e., circular/dual-polarization characteristics and multiband characteristics. These radiators have a lot of advantages, such as capability to operate multiple operating bands, reducing multipath fading, and orientation insensitive. In open literature, there are three important methods available to create multiband features in dielectric resonator antenna, i.e., (i) grouping of DRA with other radiating elements, i.e., hybrid structure ; (ii) grouping of DRA with resonating element which is not directly connected to feeding structure ; (iii) multiple mode excitation in DRA . Similarly, some of the research works have also been done in the area of dual-polarized/circularly polarized DRAs such as hybrid Z-shaped CDRA, aperture coupled RDRA, probefed CDRA and chamfered DRA, and rectangular DRA with square shaped slot . In this article, a hybrid rectangular dielectric resonator antenna is presented. Square ring shaped monopole is used to originate two different frequency bands at 1.95 GHz and 5.09 GHz. An inverted Lshaped printed line is used to create orthogonal modes in RDRA, i.e., T E x δ11 and TE y 1δ1 and generates
Probe feed Multi-element Multi-segment Triangular Dielectric Resonator Antenna with RCS Analysis
Journal of Circuits, Systems and Computers, 2018
The aim of the paper is to propose a design and analysis of multi-element multi-segment triangula... more The aim of the paper is to propose a design and analysis of multi-element multi-segment triangular dielectric resonator antenna (MEMS TDRA) with Radar Cross-Section (RCS). The proposed antenna has been excited through coaxial probe feed. The coaxial probe feed excites TM[Formula: see text] dominant mode fields within the TDR elements. A general guideline for wide bandwidth and high gain has been prepared for designing of MEMS TDRA. The model of the proposed MEMS TDRA has been studied through simulation (Ansoft HFSS software) and fabricated for measurement. The simulated antenna performance has good agreement with the measured one. The proposed MEMS TDRA performance has been compared with some similar type of previously published structure and found wider bandwidth and higher gain. The proposed MEMS TDRA provides monopole-like radiation pattern with nearly 39% bandwidth ([Formula: see text] dB). The average gain of 6.0 dBi has been found over the entire bandwidth. The RCS analysis ha...
Dielectric resonator‐based four‐element eight‐port MIMO antenna with multi‐directional pattern diversity
IET Microwaves, Antennas & Propagation, 2018
This work presents a four-element, eight-port cylindrical dielectric resonator antenna (cDRA) wit... more This work presents a four-element, eight-port cylindrical dielectric resonator antenna (cDRA) with multi-directional pattern diversity for wireless access point applications. Initially, a dielectric resonator is fed by two different feeding techniques to create two simultaneous orthogonal patterns. This primary radiator is combined with similar radiators in a cross-configuration to obtain an eight-port multiple-input-multiple-output (MIMO) antenna system. The antenna elements are placed in such a way that each radiator of the proposed antenna can radiate in a different direction so that the field correlation between the antenna elements is minimum. The proposed diversity antenna consists of four antenna elements and eight polarised ports. Isolation between the ports is improved by generating orthogonal modes in each cDRA and exciting each cDRA to radiate in a different direction. The similarity in simulated and measured results confirm that the proposed eight-port diversity antenna is useful for the frequency ranges between 5.6 and 5.9 GHz for wireless local area network (WLAN) applications.
International Journal of RF and Microwave Computer-Aided Engineering, 2018
This communication explains the designing of two-port based hybrid radiator for multiple-input-mu... more This communication explains the designing of two-port based hybrid radiator for multiple-input-multiple-output (MIMO) applications. Hybrid radiator includes U-shaped printed line and ring dielectric resonator antenna (ri-DRA). Wideband characteristics have been achieved by exciting both the U-shaped printed line along with ri-DRA. The U-shaped metallic line acts as a magnetic dipole and helps to excite fundamental hybrid mode (HE 11δ ) in the ri-DRA. Dual L-shaped and a rectangular defect have been created in ground plane for achieving wideband isolation over the working frequency band. Optimized Scattering parameters and far-field results are verified by fabricating and testing of antenna prototype. Experimental outcomes confirm that the proposed MIMO antenna gives wider impedance bandwidth (80%), improved port isolation (better than 18 dB), stable gain (~4 dB), and radiation pattern. Various MIMO performance factors are analyzed and instituted in the tolerable boundaries.
Progress In Electromagnetics Research C, 2016
In this article, a dual-polarized hybrid cylindrical dielectric resonator antenna (CDRA) is studi... more In this article, a dual-polarized hybrid cylindrical dielectric resonator antenna (CDRA) is studied. A ring-shaped patch along with an inverted L-strip is used to excite two different hybrid modes (HE 11δ and HE 12δ-like mode) in CDRA. HE 12δ mode in CDRA is very advantageous in terms of gain and radiation characteristics. The proposed antenna design shows triple-band characteristics, i.e., 1.88-2.06 GHz, 2.29-2.58 GHz and 2.9-3.93 GHz with the fractional bandwidth of 9.13%, 11.9% and 30.16%, respectively. Due to inverted L-strip, it shows circular polarization characteristics within the frequency range 3.3-3.55 GHz (AR < 3 dB). The simulated results are practically verified by using archetype of proposed antenna structure. The proposed antenna design is applicable to WLAN (2.4 GHz) and WiMAX (2.5/3.5 GHz) applications.
International Journal of RF and Microwave Computer-Aided Engineering, 2017
This communication investigates composite cylindrical dielectric resonator antenna (CDRA) for var... more This communication investigates composite cylindrical dielectric resonator antenna (CDRA) for various wireless applications. Three important features of proposed antenna design are (i) realization of two different hybrid modes, that is, HEM 11d and HEM 12d mode in CDRA with the help of modified annular ring printed line (work as both magnetic dipole and electric dipole), both the hybrid modes support broadside radiation characteristics (ii) suppression of HEM 21d mode, in order to reduce the cross-polarization level in H-plane of other hybrid modes (HEM 11d and HEM 12d mode) by an amount of 8-10 dB (iii) creation of triple-band attribute using the concept of composite antenna. The proposed antenna design has been fabricated and practically tested. Simulated outcomes show good agreement with measured outcomes. It works in three frequency bands, that is, 2.25-2.79 GHz, 3.1-4.0 GHz, and 5.05-5.6 GHz. The designed antenna structure is appropriate for WLAN and WiMAX applications.
Two elements dual segment cylindrical dielectric resonator antenna array with annular shaped microstrip feed
2016 Twenty Second National Conference on Communication (NCC), 2016
In this paper, a dual segment two element wideband cylindrical dielectric resonator antenna array... more In this paper, a dual segment two element wideband cylindrical dielectric resonator antenna array with annular shaped corporate feed network is presented. To enhance impedance bandwidth, multisegmentation concept with shifted center has been pragmatic. Annular shaped microstrip parallel feed with quarter wave transformer etched on a single side of the copper grounded substrate (εr=4.4) is used to excite the dielectric resonator antenna. With this arrangement, approximately 46.8 % impedance bandwidth is achieved for the proposed cylindrical DRA array. The proposed antenna array gives the appreciable gain and better radiation characteristics at resonant frequencies. To validate the proposed design, a prototype of the proposed antenna array is fabricated, according to the optimized dimensions. Simulation is performed using Ansys HFSS simulation software and a close agreement between simulation and measured results has been observed.
International Journal of Microwave and Wireless Technologies, 2016
A probe feed wideband multi-element dual segments quarter cylindrical dielectric resonator antenn... more A probe feed wideband multi-element dual segments quarter cylindrical dielectric resonator antenna (q-CDRA) in composite forms have been proposed. The q-CDRA has been introduced by splitting CDRA into four uniform quarters and multi-segmentation approach has been castoff for further improvement in bandwidth of q-CDRA. The dual segments q-CDRA has been designed and analyzed using theoretical analysis and Ansoft HFSS simulation software. Further the dual segment multi-element q-CDRAs in composite form have been designed. A coaxial probe has been placed at the center of the ground plane for the excitation of proposed multi-element and multi-segmented composite form of q-CDRA, which excite TM01δ mode in the proposed antenna. The input characteristics and radiation patterns of the proposed composite antennas have been studied and their results are compared with corresponding experimental results. Prototype of single, two, and four elements dual-segment composite q-CDRAs have been fabrica...