Area Network Applications Research Articles

Ultra-Compact Slitted Flower-Shaped Dual-Band Monopole Antenna for Modern Portable Devices

A meanderingly slitted bio-inspired (MSB)-shaped antenna is presented in this work. The footprint of the proposed MSB antenna is 12 × 10 mm2 0.12 × 0.10 λ g 2 at 2.1 G H z . The MSB antenna proposed in this operates at 2.1 GHz and 5.2 GHz frequencies with a bandwidth of 70 MHz and 570 MHz and a radiation efficiency of 52.5% and 96%, respectively, which is suitable for UMTS, radio navigation, Long Term Evolution (LTE), and 5 GHz Wireless Local Area Network (WLAN) applications. The proposed MSB antenna demonstrates a peak gain of 2.9 dBi at 5.2 GHz and an omnidirectional radiation pattern at both E-plane and H-plane in both operating bands. The fabrication and measurement of the proposed antenna prototype are presented. The parametric study of the proposed structure is performed and presented. Therefore, the proposed antenna is a promising candidate for modern portable devices.

A New Compact Dual-Polarized MIMO Antenna Using Slot and Parasitic Element Decoupling for 5G and WLAN Applications

This paper presents a compact dual-polarized multiple-input multiple-output (MIMO) antenna for fifth generation (5G) and wireless local area network (WLAN) applications. At first, a compact two-element dual-polarized MIMO antenna designed to operate at 3.5 GHz was developed. After that, some modifications were performed in the initial configuration, and a compact two-element dual-polarized MIMO was designed to operate at 3.5 and 5.35 GHz. A simple decoupling technique using parasitic element and slot was used to enhance the isolation between the radiating elements and to achieve an isolation above 18 dB over the band ranging from 3.4 to 3.6 GHz for the first antenna, and to achieve isolations above 19.8 dB over the first band ranging from 3.4 to 3.6 GHz and above 16.75 dB over the second band ranging from 5.15 to 5.85 GHz for the second antenna. Simulations were performed in the Ansoft HFSS software for numerical characterization and the prototype was fabricated with FR-4 dielectric and measured, presenting a good agreement between simulated and measured results. Furthermore, the envelope correlation coefficient (ECC) and the diversity gain (DG) were analyzed and present good results.

A Compact Dual-Band Bandpass Filter Using Coupled Microstrip Lines

In this paper, a new compact dual-band bandpass filter (DB-BPF) is proposed using parallel coupled lines. The design method is based on introducing transmission zeros (TZs) in the frequency response of a single-wideband filter. In the proposed structure, three coupled lines and a multi-mode resonator are used to realize the wide bandpass filter. Meanwhile, two coupled lines that are connected at the end and loaded by an open-circuit stub are employed to make a new notch filter. The proposed DB-BPF is designed and fabricated on Rogers RO3210 substrate for Wireless Local Area Networks (WLANs) applications. The simulation results show good agreement with measurements. The measured results exhibit two passbands centered at 2.4 and 5.2 GHz, having an insertion loss of less than 0.1 dB and 0.9 dB, respectively. Low insertion loss, compact size, and high attenuation between two passbands are the main advantages of the proposed DB-BPF.

Miniature Dual Band Button Antenna Using Cylindrical Dielectric Resonator

This paper presents miniature dual-band cylindrical dielectric resonator antenna (CDRA) based on button antenna for wireless body area network (WBAN) applications. A button antenna is designed by stacking two CDRAs (low and high permittivity) fed by coaxial probe through the ground plane and penetrates the bottom CDRA. The prime contributions of using DRAs are to enhance the performance and to provide a compact size of antenna. However, the coaxial probe realizes two radiation patterns, monopole and broadside patterns. A comprehensive validation using CST microwave studio is carried out to determine the characteristics of the proposed button antenna. In addition, to ensure that the results are acceptable to the practitioner in this field, a prototype was fabricated and tested. The superiority of the proposed antenna is confirmed by possessing 39% more compact size compared to previously reported studies, efficiency of more than 63% and bandwidth of 4.9% and 6.6% for lower and upper band, respectively. This proposed design is a promising candidate to benefit on/off body communication devices operating at 2.4 and 5.6 GHz.

A 170 MHz to 330 MHz Wideband 90 nm CMOS RC–CR Phase Shifter with Integrated On-Line Amplitude Locked Loop Calibration for Hartley Image Rejection Transceiver

A 160 MHz bandwidth 90° active RC–CR phase shifter with integrated on-line amplitude locked loop (ALL) calibration targeted to 802.11ac 5 GHz wireless local area network (WLAN) applications is presented in this paper. The quadrature phase shifter is a key component for transceivers employing the Hartley image rejection architecture. The passive RC–CR phase shifter generates the required two quadrature outputs with an accurate 90° phase shift over the required bandwidth but lack the required accuracy in amplitude matching. A 90 nm CMOS microelectronic implementation of an RC–CR phase shifter is proposed with active resistors that are adjusted by an integrated on-line ALL calibration system to maintain matching amplitudes of the quadrature outputs over the required bandwidth. The on-line ALL calibration system employs peak detectors, comparators, digital logic control, and charge pump to incrementally adjust the active resistors while converging to matched amplitudes similar to the operation of phase-locked loop with a phase-frequency detector and charge pump. The resulting 90 nm implementation supports − 40db to − 70db image rejection ratios (IMMRs) over the IF 170 MHz to 330 MHz bandwidth. The 90 nm CMOS implementation is fully functional considering process variations based on 200 Monte Carlo simulations.

An Improved Comparator Based on Current Reuse and a New Frequency Compensation Technique used in an OTA for Pipeline ADCs

In this paper, a comparator and an operational amplifier considered as essential components, constituting a 10-bit 50-MHz pipeline Analog-to-Digital Converter for Wireless Local Area Network (WLAN) applications, are described and designed. All post-layout and Monte-Carlo simulations, using a 0.35[Formula: see text][Formula: see text]m CMOS AMS process technology with [Formula: see text][Formula: see text]V supply voltage and an input common-mode range of [Formula: see text][Formula: see text]V, are achieved. An improved clocked comparator with a dynamic latch, based on a switched capacitor network, using the current reuse technique for slew rate enhancement and positive feedback for offset voltage compensation, is presented. The operational amplifier, consisting of a fully differential folded cascode operational transconductance amplifier, providing high-gain and good stability, is exhibited. A new frequency compensation technique, based on active resistors, is used to improve amplifier phase-margin. The Monte-Carlo performance results of the designed clocked comparator provide an offset voltage of [Formula: see text][Formula: see text]mV with [Formula: see text][Formula: see text]mV 3[Formula: see text] deviation, a slew rate of [Formula: see text]V/ns with [Formula: see text]V/ns 3[Formula: see text] deviation, and a propagation delay of [Formula: see text][Formula: see text]ns with [Formula: see text][Formula: see text]ns 3[Formula: see text] deviation. Monte-Carlo performance results of the designed operational amplifier provide a phase-margin of [Formula: see text], and a high-gain of [Formula: see text]dB with [Formula: see text] and [Formula: see text]dB 3[Formula: see text], respectively, by using [Formula: see text] load capacitance.

A New Metasurface Structure for Bandwidth Improvement of Antenna Array

In this paper, the design of an antenna array with enhanced bandwidth is presented. The antenna array includes 16 elements (4 x 4) based on RT5880 with height of 1.575 mm, dielectric constant of 2.2 and loss tangent of 0.0009 and it is yielded at the central frequency of 5.8 GHz for Wireless Local Area Network (WLAN) applications. In addition, in order to enhance bandwidth for antenna, the paper proposes a new metasurface. The metasurface, which is a lattice of 3 x 3 cells, is printed on a substrate of FR4 (h = 1.6 mm, ɛr = 4.4, and tanδ = 0.02) and it acts as an artificial magnetic conductor reflector. The final prototype with an overall dimension of 123 x 120 x 3.315 mm3 was fabricated and measured. The antenna witnesses an impedance bandwidth of 5.1-7.5 GHz at -10 dB (41%) and a peak gain of 17.65 dBi for measurement. The simulation results are confirmed by measurement ones to verify the performance of the proposed antenna.

Artificial Magnetic Conductor Based Miniaturized Frequency Re-configurable Dielectric Resonator Antenna for 5G and WBAN Applications

In this work a novel miniaturized frequency reconfigurable Dielectric Resonator antenna using Artificial Magnetic Conductor (AMC) surface is proposed. The prototype is set to work for 5G mid-band frequencies and Wireless Body Area Network (WBAN) applications. The work consists of two parts: firstly, the miniaturization of the prototype using AMC surface and secondly using the same AMC surface to reconfigure the frequency to another wireless application. Using AMC surface, the DR volume is reduced by 85% percent. Connecting the AMC unit cells through ideal switches (micro-trip slabs) re-configures the DR for different frequency. The overall performance observed before switching as well as after switching in both the cases is promising. The design is fabricated for performance analysis. A close agreement is reported between simulated and measured values of the reflection coefficients, radiation pattern, gain and efficiencies. The prototype has stable radiation pattern for both the operating frequencies. The impedance bandwidth values for both the resonance frequencies are 14.2% and 16% respectively. The prototype has a maximum gain of 6.8dBi and a maximum efficiency of 88%.

High-gain low-profile rectangular microstrip patch antenna with Yagi elements

ABSTRACT This paper presents a novel high gain rectangular microstrip patch antenna (RMSA) with vertically placed Yagi elements. The antenna is fed by a coaxial probe to excite TM01 fundamental waves at 2.4GHz, which is suitable for wireless local area network (WLAN) applications. In order to increase the antenna gain, Yagi elements are placed in groups of 5, on each side of the substrate in order to serveas directors for the radiating slots as well as the ground reflections. The proposed antenna offers 1.3dB gain improvement and %3 .1 impedance bandwidth increase in comparison to the plain rectangular microstrip antenna with the same specifications. The advantage of this antenna is to provide an easy and cost effective solution to increase microstrip antenna gain, particularly in 8-10dB range, without disruptingits planar structure.

Low-profile 2.4/5.8 GHz MIMO/diversity antenna for WLAN applications

ABSTRACT A low-profile multi-input-multi-output (MIMO)/diversity antenna suitable for wireless local area network (WLAN) applications is presented. In the proposed antenna, two identical elements (each of size 20 × 47 mm2) are designed to operate at 2.4 GHz and other two identical elements (each of size 20.5 × 20 mm2) at 5.8 GHz. All elements of the proposed diversity antenna are printed on 1.6 mm thick FR-4 substrate in a coplanar configuration. By optimizing the distance between the antenna elements (in horizontal and vertical directions), optimal isolation and diversity performance are achieved. Compared to a single feed dual-band antenna, the MIMO/diversity antenna has the ability to transmit or receive the 2.4 and 5.8 GHz signals simultaneously, without any external switching circuit between the module and the proposed antenna.

Performance of low level protocols in high traffic wireless body sensor networks

The rapid development of medical sensors has increased the interest in Wireless Body Area Network (WBAN) applications where physiological data from the human body and its environment is gathered, monitored, and analyzed to take the proper measures. In WBANs, it is essential to design MAC protocols that ensure adequate performance and Quality of Service (QoS). This paper investigates Medium Access Control (MAC) protocols used in WBAN, and compares their performance in a high traffic environment with respect to different QoS and network performance metrics. Such scenario can be induced in case of emergency for example, where physiological data collected from all sensors on human body should be sent simultaneously to take appropriate action. This study can also be extended to cover collaborative WBAN systems where information from different bodies is sent simultaneously leading to high traffic. OPNET simulations are performed to compare the performance of the different MAC protocols under the same experimental conditions. A new MAC scheme aiming to enhance the delay, throughput, and energy performance of the system is then proposed and compared to existing protocols, to evaluate its performance in high traffic environment.

Optimal Design of Compact Dual-Band Slot Antenna Using Particle Swarm Optimization for WLAN and WiMAX Applications

Background: A novel, small size, dual-band rectangular patch antenna with two narrow vertical slots for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) application is presented here. Methods: The proposed antenna, fed by coaxial line, has dimensions of 21.075 mm ×17 mm ×1. 6 mm. With a pair of vertical slots, the antenna is resonating in 3.5 GHz WiMAX and 5.3 GHz WLAN band. The dimensions of the ground plane, substrate, radiating patch and two slots on the patch antenna are optimized using Particle Swarm Optimization (PSO) to obtain the desired operating frequency band. Results: The proposed antenna shows good radiation characteristics at these two operating bands, making it suitable for dual-band operation. Conclusion: The same design with some different physical parameter may be suitable for other kinds of wireless services. Further, application of Defected Ground Structure (DGS) to such models may also provide better performance.

60 GHz Source for WLAN Applications Based on IEEE 802.11ad Protocol Standards

A high-power and low-noise 60 GHz impact avalanche transit time (IMPATT) source based on GaInAsP∼InP heterojunction has been proposed. The simulation experiments are done on InP based homojunction and two complementary heterojunction structures based on GaInAsP∼InP material system, for studying the static, large-signal and noise properties of those at 60 GHz. Results depicts that the highest RF power output with lowest noise level can be achieved at 60 GHz when N∼p junction based on Ga0.11In0.89As0.74P0.26∼InP anisotype heterojunction is grown on (100)-oriented p+-InP wafer having acceptor concentration of ∼1025 m−3. The proposed heterojunction IMPATT source is capable of delivering 4.79 W peak power with 23.21% efficiency with significantly low noise measure of only 12.5 dB; which is especially suitable for implementing 60 GHz source for ultra-high speed, short-range wireless local area network (WLAN) applications based on IEEE 802.11ad protocol standards.

Rectangular Zigzag Microstrip Patch Antenna with Swastik Shape DGS for WLAN, C and Ku-Band Applications

A triple band microstrip-fed patch antenna is presented which contains the radiating structure having rectangular zigzag shape patch and an altered ground structure with a swastic shape design. This modified ground plane actually acts as a defected ground structure (DGS). Both the modified ground plane and radiating patch are perfect electric conductors. The patch is imprinted on a substrate named as Epoxy Glass FR-4 having thickness 1.6 mm, relative permittivity 4.4, and loss tangent 0.0024. The designed microstrip patch antenna (MPA) is able to generate three specific operating bands viz. 11.9–13.6 GHz, 5.71–5.82 GHz, 4.5-4.6 GHz with adequate bandwidth of 1.64 GHz, 110 MHz and 100 MHz and corresponding return loss of -32dB, -23dB, -14.3dB respectively covering Wireless Local Area Network (WLAN), C-band and Ku-band applications. A parametric study has been performed for the rectangular slots located in the patch. Proposed MPA is simulated using Computer Simulation Technology Microwave Studio Version 14.0 (CST MWS V14.0). Lastly, the fabrication of the proposed antenna with optimized parameters has been accomplished and measured results for S-parameter magnitude have been discussed

PERANCANGAN ANTENA MIKROSTRIP ULTRA WIDE BAND DENGAN MATERIAL TEKSTIL UNTUK APLIKASI WIRELESS BODY AREA NETWORKS

Ultra Wide Band (UWB) microstrip antenna designed using textile materials for Wireless Body Area Network (WBAN) applications is presented. The antenna consists of stairs patches and a ground plane with a dimension of 30 mm x 30 mm. Simulation is done by compared antenna performance using cotton, denim, felt and fleece materials. In this study, the parameters considered in the analysis process are the characteristics of S 11 and gain value. Numerical evaluation based on simulation shows that the antenna performance well operated in the UWB frequency standard by FCC (3.1 - 10.6 GHz) with the bandwidth of ≥ 500 MHz. The use of felt material produces a wider bandwidth (3900 MHz). The fleece material provided a higher gain value on 6.51 dBi at the resonant frequency of 8.5 GHz.

Design and analysis of a metamaterial inspired dual band antenna for WLAN application

AbstractIn this paper, a compact, low-profile, coplanar waveguide-fed metamaterial inspired dual-band microstrip antenna is presented for Wireless Local Area Network (WLAN) application. To achieve the goal a triangular split ring resonator is used along with an open-ended stub. The proposed antenna has a compact size of 20 × 24 mm2 fabricated on an FR-4 epoxy substrate with dielectric constant (εr) 4.4. The antenna provides two distinct bands I from 2.40 to 2.48 GHz and II from 4.7 to 6.04 GHz with reflection coefficient better than −10 dB, covering the entire WLAN (2.4/5.2/5.8 GHz) band spectrum. The performance of the proposed metamaterial inspired antenna is also studied in terms of the radiation pattern, efficiency, and the realized gain. A comparative study is also presented to show the performance of the proposed metamaterial inspired antenna with respect to other conventional antenna structures in terms of overall size, bandwidth, gain, and reflection coefficient. Finally, the antenna is fabricated and tested. The simulated results show good agreement with the measured results.

Wireless body area network's application for motion detection based on Android smartwatch

Short-range, wireless communications in the vicinity of, or inside, a human body (but not limited to humans) are specified in this standard. It uses existing industrial scientific medical (ISM) bands as well as frequency bands approved by national medical and/or regulatory authorities. These sensors provide accurate and reliable information about the situation or activity occurring at any time. This high responsiveness of these sensors has made lives easy and safe. This article will perform an investigation on the WBAN's application for motion detection based on android smartwatch. The main problem is how to the sensors that attached on the human body can send of data via Bluetooth and read the motion and orientation of the body and display in the graph form. However, if the sensors do not match, the result of output display inappropriate. This article proposed method by using accelerometer and gyroscope sensors which are integrated with smartwatch to overcome the main problem. This application will display results in the form of numeric values and then convert in graph form. These results have proven that WBAN's application for motion sensing can be used for detection of motion and orientation via Bluetooth based on android smartwatch.

A fuzzy priority based congestion control scheme in wireless body area networks

Congestion management is one of the major challenges in wireless body area network (WBAN) applications. This study proposes a technique similar to the random early detection (RED) active queue management (AQM) to indicate congestion. A two-input-single-output fuzzy logic system is used to dynamically adjust the maximum drop probability (maxp) parameter of the RED algorithm, then two adaptive values the minimum threshold (minth) and the maximum threshold (maxth) are used to estimate the congestion level of each sensor nodes. We adjust send rate of the parent node with a fuzzy logical controller (FLC) based on the child's node traffic load, considering the different amounts of data being transmitted. The simulation results show that the proposed protocol achieves high performance as compared to PCCP and PHTCCP, in terms of packet loss, end-to-end delay and energy.

Low-Power Digital Baseband Transceiver Design for UWB Physical Layer of IEEE 802.15.6 Standard

This paper presents the design and implementation of ultrawideband digital baseband transceiver for wireless body area networks (WBAN) applications. The power dissipation and area of the proposed architecture are minimized by combining algorithmic and architectural level modifications. A new algorithm for Bose–Chaudhuri–Hocquenghem (BCH) encoding is implemented and the coding gain of the BCH decoder is improved by 0.5 dB, with a cost of only one percent area overhead. An area efficient, low-complexity, and low-power BCH decoder is implemented and it has 42 $\%$ lower area and 38 $\%$ lower power dissipation compared to a conventional hard-decision decoder. Other salient features of this paper include a low-complexity, low-power packet detection unit, and a low-power module for removing the shortening bits. The baseband transceiver has been designed in 90 nm CMOS technology and it has an energy efficiency of 73 pJ/bit in transmitter mode and 225 pJ/bit in receiver mode.

Determination of Directivity and Gain with Improved Performance of Smart Antenna

In wireless communication systems, smart antenna is designed to improve radiation in one direction and null out interference in other direction. This can be realized by increasing the directivity of the antenna element which leads to gain in a specific direction. At high frequency, transmission of signals is characterized with impairments. Mitigation of these signal impairments can be accomplished through the improvement of directivity and gain of smart antenna system at terahertz frequency range. This research work proposed and examined smart/ adaptive antennas array at terahertz (THz) frequency range, which can be applied for far distance communications and can be extended to the far-field region of antenna. The adaptive/smart antenna array is appropriately operational in the range of 300 GHz to 3 THz for wireless local area network (WLAN) applications that uses high-frequency (HF) radio waves. The efficiency of this adaptive array antennas system has been optimized and simulated with the aid of commercially available full-wave, Finite Element Method (FEM) based electromagnetic simulator Agilent’s Advanced Design Software (ADS).