Foundations For Microwave Engineering

Fog computing is an architectural style in which network components between devices and the cloud execute application-specific logic We present the first review on fog computing within healthcare informatics, and explore, classify, and discuss different application use cases presented in the literature For that, we categorize applications into use case classes and list an inventory of application-specific tasks that can be handled by fog computing We discuss on which level of the network such fog computing tasks can be executed, and provide tradeoffs with respect to requirements relevant to healthcare Our review indicates that: 1) there is a significant number of computing tasks in healthcare that require or can benefit from fog computing principles; 2) processing on higher network tiers is required due to constraints in wireless devices and the need to aggregate data; and 3) privacy concerns and dependability prevent computation tasks to be completely moved to the cloud These findings substantiate the need for a coherent approach toward fog computing in healthcare, for which we present a list of recommended research and development actions

Fog Computing in Healthcare–A Review and Discussion

Sensors based on the detection of small resistance variations are universally recognized as piezoresistive. Being one of the simplest, most common and most investigated classes of sensors, continuous efforts are focused on creating improved devices with higher performance that can be used in many commercial and non–commercial applications (e.g. evaluation of strain, pressure, acceleration, force etc.). Consequently, despite the fact that more than 150 years have passed since the discovery of the piezoresistive effect in some classes of metals and semiconductors, the development of such sensors remains interesting and topical. Moreover, with the advent of second–generation robotics, research on piezoresistive sensors has undergone a massive increase. This paper aims to be a short, self–consistent vademecum which would be useful to researchers and engineers, since it focuses on the fundamentals of theory, materials, and readout–circuit design pertinent to the most recent developments in the field of piezoresistive sensors.

Theory, technology and applications of piezoresistive sensors: A review

Breast cancer is the leading cause of death among females, early diagnostic methods with suitable treatments improve the 5-year survival rates significantly. Microwave breast imaging has been reported as the most potential to become the alternative or additional tool to the current gold standard X-ray mammography for detecting breast cancer. The microwave breast image quality is affected by the microwave sensor, sensor array, the number of sensors in the array and the size of the sensor. In fact, microwave sensor array and sensor play an important role in the microwave breast imaging system. Numerous microwave biosensors have been developed for biomedical applications, with particular focus on breast tumor detection. Compared to the conventional medical imaging and biosensor techniques, these microwave sensors not only enable better cancer detection and improve the image resolution, but also provide attractive features such as label-free detection. This paper aims to provide an overview of recent important achievements in microwave sensors for biomedical imaging applications, with particular focus on breast cancer detection. The electric properties of biological tissues at microwave spectrum, microwave imaging approaches, microwave biosensors, current challenges and future works are also discussed in the manuscript.

Microwave Sensors for Breast Cancer Detection

A compact hexagonal Sierpinski fractal antenna for super wideband applications is presented. It consists of hexagonal radiation patch with two iterations of Sierpinski square slots and coplanar waveguide feeding. An impedance bandwidth of 3.4–37.4 GHz is achieved. The achieved bandwidth ratio is 11:1. Desirable radiation performance characteristics including relatively stable and omni-directional radiation patterns are obtained over this range. A good agreement is achieved between the simulated and experimental results. The designed antenna has advantages of wider bandwidth and miniaturised size over the previously reported structures.

CPW-fed hexagonal Sierpinski super wideband fractal antenna

A novel and compact super wideband (SWB) exponentially tapered feed region and patch printed monopole antenna is proposed. This antenna is fed by a 50-Ω triangular tapered feed line. The antenna operates over a bandwidth of 2.5-80 GHz with a return loss of 10 dB or more. The dimensions of the proposed antenna are 40 × 30 × 1.6 mm 3 . An exponential curve is employed in the feed region and a triangular tapered feed line is used. The ground plane feed gap is optimised to 1.3 mm. The proposed tapered monopole antenna has demonstrated an ultra-large bandwidth with satisfactory radiation properties. Two particular antennas are examined, one with a rectangular feed line and another with a triangular tapered feed line. The performance of the antenna in frequency domain is investigated, and a good agreement is achieved between the simulation and experimental results. In addition, the time domain characteristics of the proposed antenna are evaluated experimentally. This antenna can be used in ultra-wideband or SWB applications.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-map.2013.0094

Printed monopole antenna with tapered feed line, feed region and patch for super wideband applications

In this article, a simple and compact dual bandnotched (DBN) super wideband (SWB) printed monopole antenna (PMA) has been proposed. The proposed antenna composed of a circular PMA, which is connected through a 50-Ω triangular tapered microstrip fed line (TTMFL) and a round-cornered finite ground plane (RCFGP). It exhibit s a very wide frequency band from 1.6–25 GHz (ratio bandwidth of 15.63:1) with a voltage standing wave ratio (VSWR) ≤2. By employing a U-shaped parasitic element (USPE) near the RCFGP and a T-shaped protruded stub (TSPS) inside the radiating patch, a single band-notched (SBN) characteristic in the frequency band of 3.2–4.4 GHz (WiMAX/C-band) is generated. In order to realize the second band-notched function for X-band satellite communication systems (7.2–8.4 GHz), a U-shaped slot (USS) has been inserted in the RCFGP. The overall dimension of the proposed antenna is 24×30×0.787 mm and occupies a relatively small space compared to the existing DBN antennas. Good agreement has been attained between predicted and measured results.

/pdf/a-compact-dual-band-notched-circular-ring-printed-monopole-nmyh7of60f.pdf

A Compact Dual Band-Notched Circular Ring Printed Monopole Antenna for Super wideband Applications

In this paper, a band-notched compact printed monopole super wideband (SWB) antenna has been designed and fabricated. The SWB antenna composed of a radiating patch with a 50 Ω triangular tapered feed line which is connected through a feed region, and a chamfered ground plane (CGP), that covers the frequency band from 0.9–100 GHz (ratio bandwidth of 111.1:1) with a reflection coefficient |S11| < −10 dB, except in the notched band of 4.7–6 GHz for Wireless local area network IEEE 802.11a and HIPERLAN/2 WLAN band. To realize the band notch characteristics a C-shape parasitic element is employed near the CGP etched with two symmetrical L-slots and placed under the radiating patch. Proposed antenna structure occupies a relatively small space (30 × 40 × 0.787 mm3) and achieved much wider impedance bandwidth as well as higher gain compared with the existing ultra wideband and SWB antennas.

Super wideband antenna with single band suppression

In technical education, laboratory components comprise an essential and integral part without which engineering education remains incomplete. Experiments conducted on laboratory equipments lend a practical touch to the theoretical knowledge acquired by the students. However, setting up a specialized laboratory consisting of sophisticated and expensive equipments such as Digital Storage Oscilloscope, Signal Generator, Spectrum Analyzer and Network Analyzer is an expensive and unaffordable proposition for many universities and engineering colleges. Sophisticated technologies incorporated in recent models of such high-end equipments enable remote access through Internet to the instruments. This concept of accessing these expensive instruments over the Internet can be exploited by setting up a Remote Laboratory. This remote laboratory system aims at not only providing an opportunity to students from distant places to conduct hardware experiments but also to take the corresponding measurements. In this work, real-time hardware experiments have been designed and implemented. These are based on modulation techniques widely employed in Communication Engineering. An interactive Graphical User Interface (GUI) environment has also been developed using Microsoft Visual Basic. This GUI is provided at the user end to facilitate the remote control and access of various instruments and experiment setups. It has been specifically designed and optimized for a low-bandwidth remote access link. The above mentioned system, as a whole, uses real-time capture of images and data from the instruments to perform experiment-related measurements.

Remote Communication Engineering Experiments Through Internet

Solar Photovoltaic (PV) power keeps changing with solar insolation(S) and ambient temperature (T) because PV cell exhibits non-linear current-voltage characteristic So the Maximum Power Point (MPP) varies with the changing S and T However with the advancement of power electronics converter technology, it is now possible to operate the PV power at its MPP in order to improve the overall efficiency This paper presents maximum power point tracking (MPPT) based on Perturb & Observe (P&O) and Fuzzy Logic Controller (FLC) for PV with dc-dc buck boost converter for the purpose of performance evaluation and comparison analysis thereof Both the algorithms were simulated in MATLAB-Simulink with 100W PV module (Solar Alpex Panel 1552P-3613G-166109) connected to buck-boost dc-dc converter The results of simulation and analysis indicate that the proposed FLC algorithms provide better MPP than that of conventional P&O method FLC algorithms significantly improve the efficiency of MPPT and provides faster responses particularly during fast changing environmental conditions besides the fact that it is simple and can be implemented with PIC Microcontroller or FPGA

Anup Kumar Gogoi

Papers

Printed monopole antenna with tapered feed line, feed region and patch for super wideband applications

A Compact Dual Band-Notched Circular Ring Printed Monopole Antenna for Super wideband Applications

Super wideband antenna with single band suppression

Remote Communication Engineering Experiments Through Internet

MPPT of solar photovoltaic cell using perturb & observe and fuzzy logic controller algorithm for buck-boost DC-DC converter