Search results

1 – 7 of 7
Article
Publication date: 7 August 2017

Partibane B., Gulam Nabi Alsath M. and Kalidoss Rajakani

This paper aims to presents the bandwidth enhancement of a hybrid slotloop antenna using a modified feed structure.

Abstract

Purpose

This paper aims to presents the bandwidth enhancement of a hybrid slotloop antenna using a modified feed structure.

Design/methodology/approach

The conventional monopole feed of the hybrid slotloop radiator is loaded with a flat microstrip patch to excite higher-order modes. The proposed antenna combines the resonant modes of the slot antenna, the loop antenna and the patch loading.

Findings

The antenna exhibits a dual-band response suitable for GSM 1800/1900 and ultrawideband (UWB) standards. The impedance bandwidth extends from 1.65 to 1.95 GHz (11.42 per cent) and 3 to 11.1 GHz (114.9 per cent). The proposed antenna has the smallest footprint with a peak gain of 5.07 dBi at 1.8 GHz and 4.97 dBi at 6 GHz. The prototype antenna is fabricated and the simulation results are validated using experimental measurements. The performance of the bandwidth-enhanced hybrid slotloop antenna is compared with that of other slot antennas.

Originality/value

Thus, a hybrid slotloop antenna with an enhanced bandwidth has been reported in this study. The conventional monopole feed of the antenna is replaced with a monopole ending with a microstrip patch load. The antenna covers the operating bands of GSM 1800/1900 and UWB. The proposed antenna has a smaller footprint compared with other wide-slot antennas reported in the literature.

Details

Circuit World, vol. 43 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 8 May 2018

Sangeetha Subbaraj, Malathi Kanagasabai, Gulam Nabi Alsath Mohammed, Yogeshwari Panneer Selvam, Saffrine Kingsly and Ramana Rao Yeragudipati Venkata

This paper aims to present the design of a compact quad-band coplanar-fed monopole antenna for tablet computer applications.

Abstract

Purpose

This paper aims to present the design of a compact quad-band coplanar-fed monopole antenna for tablet computer applications.

Design/methodology/approach

The antenna has the smallest size of 26 × 14 mm and supports GSM, Wi-Fi, WIMAX and Bluetooth. The proposed antenna consists of a coplanar fed main radiator, c-shaped stubs and parasitic meandered stub. The inverted c-shaped stubs enhance the bandwidth of upper frequencies. The resonance at 2.4 GHz is individually controlled by the coupled meandered stub.

Findings

The percentage bandwidth in the four operating bands are 8.7/4.12/27.8/13.3%. Furthermore, the antenna is integrated with the mock-up ground plane and specific absorption rate (SAR) calculations are performed. The estimated SAR is less than 1.6 W/kg for a 1 g body tissue. The gain and efficiency of the antenna are 3.56/4.37/4.97/6 dBi and 82.4/85/97.1/89.3%, respectively. The measured impedance and radiation characteristics of the fabricated prototype are in good correlation with the simulated results.

Originality/value

In the proposed work, vias and lumped elements are not used for lower band excitation, and most of the wireless applications in the tablet computers have been covered. Further, the effect of antenna with different orientation has been tested for the estimation of SAR.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 September 2018

Henridass Arun and Gulam Nabi Alsath M.

This paper aims to present the design and implementation of a circularly polarized co-planar waveguide (CPW) fed wideband pie-shaped monopole antenna for multi-antenna…

Abstract

Purpose

This paper aims to present the design and implementation of a circularly polarized co-planar waveguide (CPW) fed wideband pie-shaped monopole antenna for multi-antenna techniques. Multi-antenna techniques are promising solutions for higher data rate and enhanced reliability of wireless applications. They find numerous applications in 4G/5G networks and in most wireless standards such as wireless local area networks (WLAN), wireless fidelity and worldwide interoperability for microwave access systems to enhance the channel capacity without additional spectrum by means of multi-path propagation techniques.

Design/methodology/approach

The antenna is designed to operate at three WLAN frequency bands of 4.8, 5.2 and 5.8 GHz. The measured 10 dB impedance bandwidth of the proposed antenna element is 1.2 GHz (24.23 per cent). The proposed CPW fed, pie-shaped monopole antenna has a gain of 5.4 dB and an efficiency of 72.8 per cent at 4.8 GHz.

Findings

To use the proposed antenna in a multi-antenna environment, the antennas have to be placed in a close proximity to each other. The close proximity introduces strong mutual coupling between the antennas, which in turn degrades the performance of multi-antenna systems. A multi-antenna system with two antenna elements has been constructed with an edge to edge spacing of 0.24 λ0 (15 mm), and the mutual coupling level is −17 dB. To enhance the isolation between the antenna elements, a shorting pin-based interconnected semicircles enclosed decoupling structure is proposed, which improves the isolation by a factor of 12.67 dB at 4.8 GHz.

Originality/value

To validate the performance of the proposed multi-antenna in working environment, the performance metrics such as envelope correlation coefficient (ECC), diversity gain (DG) and total active reflection coefficient (TARC) are computed for the proposed multiple-input multiple-output (MIMO) antenna. The ECC value is 0.000366 at center frequency and below 0.09 for the entire operating bandwidth, which is well below the acceptable level of 0.5 as per 3GPP standard. The DG value lies above 9.5 dB for the entire operating bandwidths and it is well above the minimum value of 3 dB. The TARC values are calculated based on S parameters, and it proves that the proposed antenna a good candidate for the multi-antenna systems.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 July 2020

Premalatha J. and Sheela D.

This paper aims to present the design of a compact vertically polarized four-element UWB antenna suitable for MIMO communications.

Abstract

Purpose

This paper aims to present the design of a compact vertically polarized four-element UWB antenna suitable for MIMO communications.

Design/methodology/approach

The unit cell antenna is constructed using a square ring radiator excited through a stepped impedance feed. The proposed antenna covers the Ultra-wideband (UWB) spectrum ranging from 2.2 to 12.3 GHz. The isolation between the unit cell antennas in the array is enhanced using a simple microstrip line resonator. The decoupling element is connected to the ground through a via.

Findings

The proposed scheme offers at least 16 dB improvement in the port-to-port coupling. Furthermore, the four-element antenna array is constructed using a specific interlocking scheme. The proposed antenna array’s Multiple Input Multiple Output (MIMO) performance metrics are analyzed.

Originality/value

By suitably selecting the excitation port, directional radiation patterns can be realized. The combined radiation pattern covers 360 degrees. A prototype antenna array is fabricated, and the simulation results are verified using real-time experiments. The proposed antenna is a suitable candidate for shark fin housing in automotive communications.

Details

Circuit World, vol. 47 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 7 December 2022

Yokesh V., Gulam Nabi Alsath and Malathi Kanagasabai

The design, fabrication and experimental validation of defected microstrip structure (DMS) are proposed to address the problem of near-end crosstalk (NEXT) and far-end…

Abstract

Purpose

The design, fabrication and experimental validation of defected microstrip structure (DMS) are proposed to address the problem of near-end crosstalk (NEXT) and far-end crosstalk (FEXT) between the microstrip transmission lines in a printed circuit board.

Design/methodology/approach

The proposed DMS evolved with the combination of spur line (L-shaped DMS) and U-shaped DMS topologies. This technique reduces the strength of electromagnetic coupling and suppresses crosstalk by optimizing the capacitive and inductive coupling ratio between the linked microstrip lines. The practical inductance value is much more significant in DMS than in defected ground structures (DGS), but the capacitance value remains the same.

Findings

A DMS unit is etched on the aggressor microstrip line instead of the DGS circuit. Because there is no leakage via the ground plane and the circuit size is far smaller than with DGS, the enclosure issue is disregarded. DMS structures have a larger effective inductance and are resistant to electromagnetic interference. A tightly coupled transmission line structure with minimal separation between the coupled microstrip line is designed using DMS. Further research must be conducted to improve the NEXT, FEXT and spacing between the transmission lines.

Originality/value

Simulation and actual measurement results show that the proposed DMS structure can effectively suppress crosstalk by analysing the S-parameters, namely, S_12, S_13 and S_14, with measured values of 1.48 dB, 20.65 dB and 21.099 dB, respectively. The data rate is measured to be 1.34 Gbps as per the eye diagram characterization. The results show that the NEXT and FEXT are reduced by approximately 20 dB in the frequency range of 1–11 GHz for mixed signals. The substantial measured results in the vector network analyser coincide with the computer simulation technology microwave studio suite simulation results.

Details

Microelectronics International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 27 October 2021

Yokesh V., Gulam Nabi Alsath Mohammed and Malathi Kanagasabai

The purpose of this paper is to design a suitable guard trace to reduce the electromagentic interference between two closely spaced high frequency transmission lines. A…

Abstract

Purpose

The purpose of this paper is to design a suitable guard trace to reduce the electromagentic interference between two closely spaced high frequency transmission lines. A novel cross-shaped resonator combined via fence is passed down to alleviate far-end and near-end crosstalk (NEXT) in tightly coupled high-speed transmission lines. The distance between the adjacent transmission lines is increased stepwise as a function of trace width.

Design/methodology/approach

A rectangular-shaped resonator via fence is connected by a guard trace has been proposed to overcome the coupling between the traces that is separated by 2 W. Similarly, by creating a cross-shaped resonator via fence connected by guard trace that reduces the spacing further by 1.5 W.

Findings

A tightly coupled transmission line structure that needs separation by a designed unit cell structure. Further research needs to be conducted to improve the NEXT, far-end crosstalk (FEXT) and spacing between the transmission lines.

Originality/value

This study portrays a novel method that combines the resonators via fence with a minimum spacing between the tightly coupled transmission lines which reduce the NEXT and FEXT; thereby reducing the size of the routing area. The resultant test structures are characterized at high frequencies using time domain and frequency domain analysis. The following scattering parameters such as insertion loss, NEXT and FEXT of the proposed method are measured as 1.504 dB, >30 dB and >20 dB, respectively.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 23 February 2018

Kirubaveni Savarimuthu, Radha Sankararajan, Gulam Nabi Alsath M. and Ani Melfa Roji M.

This paper aims to present the design of a cantilever beam with various kinds of geometries for application in energy harvesting devices with a view to enhance the…

Abstract

Purpose

This paper aims to present the design of a cantilever beam with various kinds of geometries for application in energy harvesting devices with a view to enhance the harvested power. The cantilever beams in rectangular, triangular and trapezoidal geometries are simulated, designed and evaluated experimentally. A power conditioning circuit is designed and fabricated for rectification and regulation.

Design/methodology/approach

The analytical model based on Euler–Bernoulli beam theory is analyzed for various cantilever geometries. The aluminum beam with Lead Zirconate Titanate (PZT) 5H strip is used for performing frequency, displacement, strain distribution, stress and potential analysis. A comparative analysis is done based on the estimated performance of the cantilevers with different topologies of 4,500 mm3 volume.

Findings

The analysis shows the trapezoidal cantilever yielding a maximum voltage of 66.13 V at 30 Hz. It exhibits maximum power density of 171.29 W/mm3 at optimal resistive load of 330 kΩ. The generated power of 770.8 µW is used to power up a C-mote wireless sensor network.

Originality/value

This study provides a complete structural analysis and implementation of the cantilever for energy harvesting application, integration of power conditioning circuit with the energy harvester and evaluation of the designed cantilevers under various performance metrics.

Details

Circuit World, vol. 44 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

1 – 7 of 7