Search results

This paper aims to state the configuration of the proposed antenna which is competent to many networks such as LTE and X band applications. The experimental study encountered the significance of the proposed antenna.

A novel compact Kuznets curve with parabola-shaped quad-band notched antenna is demonstrated in this paper. The presented prototype is ascertained on a composite material composed of woven fiberglass cloth with an epoxy resin binder. The resulting ultra-wideband antenna ranges 3.1–3.54 GHz, 5.17–5.51 GHz, 5.74–6.43 GHz and 6.79–7.60 GHz. To avoid the frequency bands which cause UWB interference,the projected antenna has been incorporated with slotted patch. The proposed antenna design is attained in four steps. The simple circular patch antenna model with defected ground plane is subjected to stepwise progression by including parabola-shaped slot and U shaped slot on the patch to attain four notched bands.

This projected antenna possesses an optimal bond among simulated and measured outcomes,which is more suitable for the quad notched band applications. Substrate analysis is done by varying substrate material, and notch behavior is presented. The proposed method’s optimum performance in metrics such as return loss, voltage standing wave ratio and radiation pattern varies its frequency range from 2.56 to 7.6 GHz.

The antenna adaptation of the defected ground plane has achieved through the quad notched band with operating frequency ranges 2.56 to 7.6 GHz and with eliminated frequency ranges 3.55–5.16 GHz, 5.52–5.73 GHz, 6.44–6.78 GHz and 7.66–10.6 GHz.

This paper aims to present a low-cost, edge-fed, windmill-shaped, notch-band eliminator, circular monopole antenna which is practically loaded with a complementary split ring resonator (CSRR) in the middle of the radiating conductor and also uses a partial ground to obtain wide-band performance.

To compensate for the reduced value of gain and reflection coefficient because of the full (complete) ground plane at the bottom of the substrate, the antenna is further loaded with a partial ground and a CSRR. The reduction in the length of ground near the feed line improves the impedance bandwidth, and introduced CSRR results in improved gain with an additional resonance spike. This results in a peak gain 3.895dBi at the designed frequency 2.45 GHz. The extending of three arms in the circular patch not only led to an increase of peak gain by 4.044dBi but also eliminated the notch band and improved the fractional bandwidth 1.65–2.92 GHz.

The work reports a –10dB bandwidth from 1.63 GHz to 2.91 GHz, which covers traditional coverage applications and new specific uses applications such as narrow LTE bands for future internet of things (NB-IoT) machine-to-machine communications 1.8/1.9/2.1/2.3/2.5/2.6 GHz, industry, automation and business-critical cases (2.1/2.3/2.6 GHz), industrial, society and medical applications such as Wi-MAX (3.5 GHz), Wi-Fi3 (2.45 GHz), GSM (1.9 GHz), public safety band, Bluetooth (2.40–2.485 GHz), Zigbee (2.40–2.48Ghz), industrial scientific medical (ISM) band (2.4–2.5 GHz), WCDMA (1.9, 2.1 GHz), 3 G (2.1 GHz), 4 G LTE (2.1–2.5 GHz) and other personal communication services applications. The estimated RLC electrical equivalent circuit is also presented at the end.

Because of full coverage of Bluetooth, Zigbee, WiFi3 and ISM band, the proposed fabricated antenna is suitable for low power, low data rate and wireless/wired short-range IoT-enabled medical applications.

The antenna is fabricated on a piece (66.4 mm × 66.4 mm × 1.6 mm) of low-cost low profile FR-4 epoxy substrate (0.54 λ_g × 0.54 λ_g) with a dielectric constant of 4.4, a loss tangent of 0.02 and a thickness of 1.6 mm. The antenna reflection coefficient, impedance and VSWR are tested on the Keysight technology (N9917A) vector network analyzer, and the radiation pattern is measured in an anechoic chamber.

In wireless communication system, use of multiple antennas for different requirements of system will increase the system complexity. However, reconfigurable antenna is maximizing the connectivity to cover different wireless services that operate different frequency range. Pattern reconfigurable antenna can improve security, avoid noise and save energy. Due to their compactness and better performance at different applications, reconfigurable antennas are very popular among the researchers. The purpose of this work, is to propose a novel design of S-shaped antenna with frequency and pattern diversity. The pattern and frequency reconfiguration are controlled via ON/OFF states of the PIN diode.

The geometrical structure of the proposed antenna dimension is 18 × 18 × 0.787 mm³ with εr = 2.2 dielectric constant. Three S-shaped patches are connected to a ring patch through PIN diodes. The approximate circumference of ring patch is 18.84 mm and length of patch is 5 mm, so approximate length of radiating patch is 14.42 mm and effective dielectric constant is 1.93. Conductor backed coplanar waveguide (CPW) is used for feeding. The proposed antenna is designed and simulated on CST microwave studio and fabricated using photolithography process. Measurements have been done in anechoic chamber.

Antenna shows the dual band operation at 2.1 and 3.4 GHz frequency. The first band remains constant at 2.1 GHz resonant frequency and 200–400 MHz impedance bandwidth. Second band is switched at seven different resonant frequencies as 3.14, 3.45, 3.46, 3.68, 3.69, 3.83 and 3.86 GHz with switching of the diodes. The −10 dB bandwidth is more than 1.4 GHz.

Pattern reconfigurability can be achieved using mechanical movement of antenna easily but it is not a reliable approach for planar antennas. Electronic switching method is used in proposed antenna. Antenna size is very small so fabrication is very crucial task. Measured results are deviated from simulation results due to fabrication error and effect of leads of diodes, connecting wires and battery.

The reconfiguration of the proposed antenna is controlled via ON/OFF states of the three PIN diodes. The lower band of 2.1 GHz is fixed, while second band is switched at five different resonant frequencies as 3.27, 3.41, 3.45, 3.55 and 3.88 GHz, with switching of the PIN diodes with all state of diodes and exhibit pattern reconfigurability at 2.1 GHz frequency. At second band center frequency is significantly changed with state of diodes and at 3.4 GHz pattern is also changed with state of diodes, hence antenna exhibits frequency and pattern reconfigurability.

A novel design of pattern and frequency reconfigurable antenna is proposed. Here, work is divided into two parts: first is frequency reconfiguration and second is radiation pattern reconfiguration. PIN diodes as switch are used to select the frequency band and reconfigure the radiation pattern. This proposed antenna design is novel dual band frequency and pattern reconfigurable antenna. It resonates at two distinct frequencies, i.e. 2.1 and 3.4 GHz, and has a pattern tilt from 0° to 355°. The conductor backed CPW feed technique is used for impedance matching.

Municipal wireless networks (MWN) strive to provide broader access to the internet with some form of governmental support, usually from a city. They have generated considerable interest this decade with hundreds being launched, and recently have garnered notoriety with the withdrawal of providers like EarthLink, MetroFi, and Kite from the MWN market leaving a number of large cities like Philadelphia, San Francisco, and Portland, OR, scrambling with half completed systems, and many other cities scuttling ambitious plans to “carpet” their jurisdictions. This paper discusses the rationale for providing a public service in general; the specific arguments used for and against municipalities developing MWNs; and the various most common business models. We then briefly review the Philadelphia case and contrast it with the case of Riverside, CA, which employs a different business model. We conclude by reviewing the generalizations that can be made about the policies surrounding MWNs at this point in their evolution.

The aftermath of hurricane Katrina has reinforced the role of communication networks and information management in providing effective response to a large‐scale disaster. The purpose of this paper is to examine the performance of communication networks and information systems during hurricane Katrina, list causes of failure and propose design for reliable and scalable networks.

A detailed study of communication networks and information systems was undertaken in the Gulf Coast area.

Breakdown of backhaul circuits, flooding of PSTN and disruption of electricity contributed to failure of communication systems. Overall wireless voice and data networks had faster recovery time and performed better than the landline networks. Absence of inter‐agency information system contributed towards delayed response.

During the reconstruction activity in Gulf Coast and to prepare strategy for disasters in future, officials will need to refocus on the design of networks and information management systems so as to improve inter‐agency communication, speed up recovery efforts and limit loss in business value.

It is imperative that organizations involved in the disaster recovery process have all the information they need – quickly and accurately. Quick response to disaster has the potential to significantly reduce total loss. This paper proposes integrated disaster management strategies for coordinated response to disaster.

The recent advancement in gait analysis combines internet of things that provides better observations of person living behavior. The biomechanical model used for elderly and physically challenged persons is related to gait-related parameters, and the accuracy of the existing systems significantly varies according to different person abilities and their challenges. The paper aims to discuss these issues.

Deployment of wearable sensors in gait analysis provides a better solution while tracking the changes of the personal style, and this proposed model uses an electronics system using force sensing resistor and body sensors.

Experimental results provide an average gait recognition of 95 percent compared to the existing neural network-based gait analysis model based on the walking speeds and threshold values.

The sensors are used to monitor and update the predicted values of a person for analysis. Using IoT a communication process is performed in the research work by identifying a physically challenged person even in crowded areas.

The purpose of this paper is to analyze the effect of privacy and perceived security on the level of trust shown by the consumer in the internet. It also aims to reveal and test the close relationship between the trust in a web site and the degree of loyalty to it.

First, there is an explanation of the main attributes of the concepts examined, with special attention being paid to the multi‐dimensional nature of the variables and the relationships between them. This is followed by an examination of the validation processes of the measuring instruments.

Specifically, the study reveals that an individual's loyalty to a web site is closely linked to the levels of trust. Thus, the development of trust not only affects the intention to buy, as shown by previous researchers, but it also directly affects the effective purchasing behavior, in terms of preference, cost and frequency of visits, and therefore, the level of profitability provided by each consumer. In addition, the analyses show that trust in the internet is particularly influenced by the security perceived by consumers regarding the handling of their private data.

The results of this study provide several managerial implications for companies in this sector. Suggestions are offered for national and international organizations involved in regulating these markets.

The results of this research remedy, to a certain extent, the scarcity of empirical studies that have designed and validated measuring scales for the concepts of privacy, security, trust and loyalty to the internet, as well as testing the relationships between them.

In many cases it is not appropriate to utilise a system of daily route scheduling. This paper looks at the situation where a fixed route system is required and the demand characteristics of the customers must be matched to the system.

Presents a review of the world's largest combined trade show and poly/technical forum, ITU Telecom 2003, which was held on 12‐13 October in Geneva. Reveals that there appears to be a migration towards an Internet ‐centric network, wireless technologies are becoming more developed and there is an increase in broadband access.