Antenna Theory And Design

As new fabrication and integration technologies reduce the cost and size of micro-sensors and wireless interfaces, it becomes feasible to deploy densely distributed wireless networks of sensors and actuators. These systems promise to revolutionize biological, earth, and environmental monitoring applications, providing data at granularities unrealizable by other means. In addition to the challenges of miniaturization, new system architectures and new network algorithms must be developed to transform the vast quantity of raw sensor data into a manageable stream of high-level data. To address this, we propose a tiered system architecture in which data collected at numerous, inexpensive sensor nodes is filtered by local processing on its way through to larger, more capable and more expensive nodes.We briefly describe Habitat monitoring as our motivating application and introduce initial system building blocks designed to support this application. The remainder of the paper presents details of our experimental platform.

Habitat monitoring: Application driver for wireless communications technology

Description: Electrical Engineering/Antennas and Propagation Microstrip Antennas The Analysis and Design of Microstrip Antennas and Arrays Microstrip Antennas contains valuable new information on antenna design and an excellent introduction to the work done in the microstrip antenna area over the past 20 years. The articles are well–chosen and (are) complete with practical design information that is very useful for the working engineer. Stuart Long, University of Houston The editors have done an outstanding job in assembling this updated reprint book. It is a welcome addition to the list of books on microstrip antennas. There is no doubt that it will be a valuable source of information for graduate students, engineers and researchers the original articles are written lucidly and are very informative, and the reprint articles are well chosen. Kai Fong Lee, The University of Toledo Complete with an up–to–date tutorial overview of the field and substantial new, introductory material for each topic, Microstrip Antennas combines in one source a selection of today’s most significant and useful articles on microstrip and antenna design. Eminent experts David M. Pozar and Daniel H. Schaubert guide you through:

Microstrip Antennas The Analysis And Design Of Microstrip Antennas And Arrays

As one of the transition metal oxides, niobium pentoxide (Nb2O5) offers a broad variety of properties that make it a potentially useful and highly applicable material in many different areas. In comparison to many other transition metal oxides, Nb2O5 has received relatively little attention, which presents a significant opportunity for future investigations aimed at fundamentally understanding this material and finding new and interesting applications for it. In this article, a general overview of Nb2O5 is presented which focuses on its fundamental properties, synthesis methods and recent applications, along with a discussion on future research directions relevant to this material.

Thin films and nanostructures of niobium pentoxide : fundamental properties, synthesis methods and applications

Wearable devices provide an alternative pathway to clinical diagnostics by exploiting various physical, chemical and biological sensors to mine physiological (biophysical and/or biochemical) information in real time (preferably, continuously) and in a non-invasive or minimally invasive manner. These sensors can be worn in the form of glasses, jewellery, face masks, wristwatches, fitness bands, tattoo-like devices, bandages or other patches, and textiles. Wearables such as smartwatches have already proved their capability for the early detection and monitoring of the progression and treatment of various diseases, such as COVID-19 and Parkinson disease, through biophysical signals. Next-generation wearable sensors that enable the multimodal and/or multiplexed measurement of physical parameters and biochemical markers in real time and continuously could be a transformative technology for diagnostics, allowing for high-resolution and time-resolved historical recording of the health status of an individual. In this Review, we examine the building blocks of such wearable sensors, including the substrate materials, sensing mechanisms, power modules and decision-making units, by reflecting on the recent developments in the materials, engineering and data science of these components. Finally, we synthesize current trends in the field to provide predictions for the future trajectory of wearable sensors. 

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End-to-end design of wearable sensors

This paper reports on reduced graphene oxide (rGO), tin oxide (SnO2) and polyvinylidene fluoride (PVDF) tertiary nanocomposite thick film based flexible gas sensor. The nanocomposite of 0.90(PVDF) − 0.10[x(SnO2) − (1 − x)rGO] with different weight percentages (x = 0, 0.15, 0.30, 0.45, 0.6, 0.75, 0.90 and 1) have been prepared by the hot press method. Chromium (Cr) has been deposited on the surface by using E-beam evaporation system, which is used as electrode of the device. Crystal structure, morphology, and electrical characteristics of the device have been explored for the technological application. A correlation between crystallinity, morphology, and electrical properties with these thick films has also been established. The device has been tested at different hydrogen (H2) gas concentration as well as at different response times. A superior response of 0.90(PVDF) − 0.10[0.75(SnO2) − 0.25 rGO] nanocomposite thick film has been observed. Hence, this composition is considered as optimized tertiary nanocomposite for the hydrogen gas sensor application. The sensor response of 49.2 and 71.4% with response time 34 sec and 52 sec for 100 PPM and 1000 PPM H2 gas concentration respectively have been obtained. First time a new kind of low cost and flexible polymer based nanocomposite thick film gas sensor has been explored.

A new type low-cost, flexible and wearable tertiary nanocomposite sensor for room temperature hydrogen gas sensing.

Improvement in performance of lead free inverted perovskite solar cell by optimization of solar parameters

An ultrasensitive ammonia gas sensor based on hydrothermally synthesized rGO/WO3 nanocomposite with interdigitated chromium electrode has been fabricated. Device properties such as structural, morphological, optical, and electrical were analyzed and reported. A correlation between stability and performance of the device with electrical properties has been established. Sensor shows excellent selectivity and sensitivity towards ammonia detection, even at lower gas concentration and low operating temperature. At room temperature, the sensor depicts the sensing response 4.35 with 13/20 sec response/recovery time for 10 PPM NH3 gas concentration. Although the best sensing performance has been obtained for 150 °C operating temperature. For 10 PPM and 100 PPM NH3 gas concentration, we found sensor response 10.89 and 27.7 with 11/17 and 7/19 sec response/recovery time. The sensor has been tested for different period/interval of time and found that the proposed nanocomposite has excellent stability and reproducibility thus can be utilized for various gas sensing applications.

Sensitivity Enhancement of Ammonia Gas Sensor Based on Hydrothermally Synthesized rGO/WO 3 Nanocomposites

This paper reports a comparative study of electron-beam evaporated ZnO, MgZnO, and CdZnO thin film based-gas sensor. At room temperature (RT), these semi-conductive thin films were deposited on Si/SiO2 substrate and an interdigitated pattern of chromium electrode deposited on these films. Device properties, such as structural, optical, and electrical, have been reported and analyzed. The sensors have been tested at different operating temperatures. At 250 °C, the sensor shows the best response for CdZnO thin films. We have obtained sensor response 4.86 with response time 15 sec for 100-PPM carbon mono oxide (CO) gas concentration for CdZnO thin film. Based on experimental results, Cd-doped ZnO has been found most suitable among these semiconducting metal oxides, when used as a CO gas sensor. A correlation between structural, optical, and electrical properties with these thin films has also been established.

CO Gas Sensor Based on E-Beam Evaporated ZnO, MgZnO, and CdZnO Thin Films: A Comparative Study

An accident is a deviation from expected behavior of event that adversely affects the property, living body or persons and the environment. Security in vehicle to vehicle communication or travelling is primary concern for everyone. The work presented in this article documents the designing of an accident detection system. The accident detection system design informs the police control room or any other emergency calling system about the accident. An accelerometer sensor has been used to detect abrupt change in g-forces in the vehicle due to accident. When the range of gforces comes under the accident severity, then the microcontroller activates the GSM modem to send a prestored SMS to a predefined phone number. Also a buzzer is switched on. The product design was tested in various conditions. The test result confirms the stability and reliability of the system.

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Deepak Punetha

Papers

A new type low-cost, flexible and wearable tertiary nanocomposite sensor for room temperature hydrogen gas sensing.

Improvement in performance of lead free inverted perovskite solar cell by optimization of solar parameters

Sensitivity Enhancement of Ammonia Gas Sensor Based on Hydrothermally Synthesized rGO/WO 3 Nanocomposites

CO Gas Sensor Based on E-Beam Evaporated ZnO, MgZnO, and CdZnO Thin Films: A Comparative Study

Design and Realization of the Accelerometer based Transportation System (ATS)