New Frontiers in the Use of Microwave Energy: Power and Metrology

1988 ◽  
Vol 124 ◽  
Author(s):  
Ralph W. Bruce
Keyword(s):  
Radio Frequency ◽  
Low Cost ◽  
Short Review ◽  
Microwave Energy ◽  
Electromagnetic Spectrum ◽  
Electromagnetic Heating ◽  
Microwave Radio ◽  
Rf Energy

ABSTRACTThe Microwave/Radio Frequency portion of the electromagnetic spectrum has been used principally for the transmission and reception of information in communications and radar. With the advent of low cost commercial and consumer items (satellite downlinks and microwave ovens) has also come a resurgence of interest in using the energy and properties of these frequencies for other important tasks.The purpose of this paper is to give a short review of the basics of electromagnetic heating and an overview of new trends in this use of microwave/RF energy. These trends can be divided into two broad categories: power and metrology.

Peel-and-Stick Sensors Powered by Directed Radio-Frequency Energy

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
David Eric Schwartz ◽  
Clinton J. Smith ◽  
Joseph Lee ◽  
Shakthi Priya Gowri ◽  
George Daniel ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Wireless Sensors ◽  
High Performance ◽  
Energy Savings ◽  
Low Cost ◽  
Sensor Nodes ◽  
Sensor Localization ◽  
Radio Frequency Energy ◽  
Commission Regulation ◽  
Rf Energy

PARC, a Xerox Company, is developing a low-cost system of peel-and-stick wireless sensors that will enable widespread building environmental sensor deployment with the potential to deliver up to 30% energy savings. The system is embodied by a set of radio-frequency (RF) hubs that provide power to automatically located sensor nodes and relay data wirelessly to the building management system (BMS). The sensor nodes are flexible electronic labels powered by rectified RF energy transmitted by the RF hub and can contain multiple printed and conventional sensors. The system design overcomes limitations in wireless sensors related to power delivery, lifetime, and cost by eliminating batteries and photovoltaic devices. Sensor localization is performed automatically by the inclusion of a programmable multidirectional antenna array in the RF hub. Comparison of signal strengths as the RF beam is swept allows for sensor localization, reducing installation effort and enabling automatic recommissioning of sensors that have been relocated. PARC has already demonstrated wireless power and temperature data transmission up to a distance of 20 m with 71 s between measurements, using power levels well within the Federal Communications Commission regulation limits in the 902–928 MHz industrial, medical and scientific (ISM) band. The sensor's RF energy harvesting antenna achieves high performance with dimensions of 5 cm × 9.5 cm.

scholarly journals Fabry-Perot Cavity Leaky Wave Antennas with Tunable Features for Terahertz Applications

2020 ◽  
Vol 5 (1) ◽  
pp. 11 ◽  
Author(s):  
Silvia Tofani ◽  
Walter Fuscaldo
Keyword(s):  
Technological Development ◽  
Low Cost ◽  
Short Review ◽  
Thz Radiation ◽  
Electromagnetic Spectrum ◽  
Optical Parameters ◽  
Leaky Wave ◽  
Practical Applications ◽  
Fabry Perot ◽  
Thz Antennas

Terahertz (THz) radiation is a very appealing band of the electromagnetic spectrum due to its practical applications. In this context, the THz generation and manipulation is an essential part of the technological development. The demand of THz antennas is still high because it is already difficult to obtain directive, efficient, planar, low-cost, and easy-to-fabricate THz radiating systems. In this regard, Fabry-Perot cavity leaky-wave antennas are gaining increasing attention at THz, due to their very interesting radiating features: the combination of planar designs with metamaterials and metasurfaces could offer a promising platform for future THz manipulation technologies. In this short review, we focus on different classes of leaky-wave antennas, based on materials with tunable quasi-optical parameters. The possibility of producing directive patterns with particularly good efficiencies, as well as the capability of dynamically reconfiguring their radiating features, are discussed by taking into account the risk of increasing costs and fabrication complexity.

Sitsen: Passive sitting posture sensing based on wireless devices

2021 ◽  
Vol 17 (7) ◽  
pp. 155014772110248
Author(s):  
Miaoyu Li ◽  
Zhuohan Jiang ◽  
Yutong Liu ◽  
Shuheng Chen ◽  
Marcin Wozniak ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
High Performance ◽  
Learning Algorithm ◽  
Low Cost ◽  
Recognition System ◽  
Sitting Posture ◽  
Average Accuracy ◽  
Phase Variations ◽  
Window Approach

Physical health diseases caused by wrong sitting postures are becoming increasingly serious and widespread, especially for sedentary students and workers. Existing video-based approaches and sensor-based approaches can achieve high accuracy, while they have limitations like breaching privacy and relying on specific sensor devices. In this work, we propose Sitsen, a non-contact wireless-based sitting posture recognition system, just using radio frequency signals alone, which neither compromises the privacy nor requires using various specific sensors. We demonstrate that Sitsen can successfully recognize five habitual sitting postures with just one lightweight and low-cost radio frequency identification tag. The intuition is that different postures induce different phase variations. Due to the received phase readings are corrupted by the environmental noise and hardware imperfection, we employ series of signal processing schemes to obtain clean phase readings. Using the sliding window approach to extract effective features of the measured phase sequences and employing an appropriate machine learning algorithm, Sitsen can achieve robust and high performance. Extensive experiments are conducted in an office with 10 volunteers. The result shows that our system can recognize different sitting postures with an average accuracy of 97.02%.

Carbon Dioxide as a Carbon Resource – Recent Trends and Perspectives

2012 ◽  
Vol 67 (10) ◽  
pp. 961-975 ◽  
Author(s):  
Markus Hölscher ◽  
Christoph Gürtler ◽  
Wilhelm Keim ◽  
Thomas E. Müller ◽  
Martina Peters ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Raw Materials ◽  
Low Cost ◽  
Polymeric Materials ◽  
Short Review ◽  
Chemical Research ◽  
Bond Forming ◽  
Bulk Chemicals ◽  
High Thermodynamic Stability ◽  
Recent Trends

With the growing perception of industrialized societies that fossil raw materials are limited resources, academic chemical research and chemical industry have started to introduce novel catalytic technologies which aim at the development of economically competitive processes relying much more strongly on the use of alternative carbon feedstocks. Great interest is given world-wide to carbon dioxide (CO2) as it is part of the global carbon cycle, nontoxic, easily available in sufficient quantities anywhere in the industrialized world, and can be managed technically with ease, and at low cost. In principle carbon dioxide can be used to generate a large variety of synthetic products ranging from bulk chemicals like methanol and formic acid, through polymeric materials, to fine chemicals like aromatic acids useful in the pharmaceutical industry. Owing to the high thermodynamic stability of CO2, the energy constraints of chemical reactions have to be carefully analyzed to select promising processes. Furthermore, the high kinetic barriers for incorporation of CO2 into C-H or C-C bond forming reactions require that any novel transformation of CO2 must inevitably be associated with a novel catalytic technology. This short review comprises a selection of the most recent academic and industrial research developments mainly with regard to innovations in CO2 chemistry in the field of homogeneous catalysis and processes.

scholarly journals Design of a Multiband Global Navigation Satellite System Radio Frequency Interference Monitoring Front-End with Synchronized Secondary Sensors

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2594
Author(s):  
Aiden Morrison ◽  
Nadezda Sokolova ◽  
James Curran
Keyword(s):  
Radio Frequency ◽  
Global Navigation Satellite System ◽  
Low Cost ◽  
Satellite System ◽  
Radio Frequency Interference ◽  
Navigation Satellite ◽  
Inertial Measurement ◽  
Front End ◽  
Global Navigation ◽  
Global Navigation Satellite

This paper investigates the challenges of developing a multi-frequency radio frequency interference (RFI) monitoring and characterization system that is optimized for ease of deployment and operation as well as low per unit cost. To achieve this, we explore the design and development of a multiband global navigation satellite system (GNSS) front-end which is intrinsically capable of synchronizing side channel information from non-RF sensors, such as inertial measurement units and integrated power meters, to allow the simultaneous production of substantial amounts of sampled spectrum while also allowing low-cost, real-time monitoring and logging of detected RFI events. While the inertial measurement unit and barometer are not used in the RFI investigation discussed, the design features that provide for their precise synchronization with the RF sample stream are presented as design elements worth consideration. The designed system, referred to as Four Independent Tuners with Data-packing (FITWD), was utilized in a data collection campaign over multiple European and Scandinavian countries in support of the determination of the relative occurrence rates of L1/E1 and L5/E5a interference events and intensities where it proved itself a successful alternative to larger and more expensive commercial solutions. The dual conclusions reached were that it was possible to develop a compact low-cost, multi-channel radio frequency (RF) front-end that implicitly supported external data source synchronization, and that such monitoring systems or similar capabilities integrated within receivers are likely to be needed in the future due to the increasing occurrence rates of GNSS RFI events.

scholarly journals Removal of Orange G Dye from Aqueous Solution by Adsorption: A Short Review

2020 ◽  
Vol 9 (1) ◽  
pp. 318-327
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Low Cost ◽  
Short Review ◽  
Industrial Wastes ◽  
Present Review ◽  
Wastewater Remediation ◽  
Experimental Conditions ◽  
Adsorption Capacities ◽  
Orange G

Adsorption is a widely used technique for wastewater remediation. The process is effective and economical for the removal of various pollutants from wastewater, including dyes. Moreover, Besides commercial activated carbon, different low-cost materials such as agricultural and industrial wastes are now used as adsorbents. The present review focused on the removal of a teratogenic and carcinogenic dye, orange G (OG) via adsorption using several adsorbents, together with the experimental conditions and their adsorption capacities. Based on the information compiled, various adsorbents have shown promising potential for OG removal.

Low-cost millimeter-wave radio-frequency sensors: New applications enabled by developments in low cost chipsets

2017 ◽  
Author(s):  
Chris Roff ◽  
James R. Henderson ◽  
Damien Clarke ◽  
Marcus C. Walden ◽  
Steve Fitz
Keyword(s):  
Radio Frequency ◽  
Millimeter Wave ◽  
Low Cost ◽  
Wave Radio ◽  
New Applications
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