Radio frequency optoelectronic receiver for high-performance analog systems

1996 ◽  
Author(s):  
Daniel Yap ◽  
Y-M. Xie ◽  
Robert H. Walden ◽  
Y. K. Brown ◽  
M. B. Kardos ◽  
...  
2021 ◽  
Vol 17 (7) ◽  
pp. 155014772110248
Author(s):  
Miaoyu Li ◽  
Zhuohan Jiang ◽  
Yutong Liu ◽  
Shuheng Chen ◽  
Marcin Wozniak ◽  
...  

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%.


Nanoscale ◽  
2017 ◽  
Vol 9 (33) ◽  
pp. 11944-11950 ◽  
Author(s):  
Mehrdad Shaygan ◽  
Zhenxing Wang ◽  
Mohamed Saeed Elsayed ◽  
Martin Otto ◽  
Giuseppe Iannaccone ◽  
...  

Metal–insulator–graphene diodes are proved to be able to deliver high performance, and meanwhile are suitable for radiofrequency power detection.


2018 ◽  
Vol 89 (4) ◽  
pp. 560-571 ◽  
Author(s):  
Xiaochen Chen ◽  
Leena Ukkonen ◽  
Johanna Virkki

Passive radio frequency identification-based technology is a convincing approach to the achievement of versatile energy- and cost-efficient wireless platforms for future wearable applications. By using two-part antenna structures, the antenna-electronics interconnections can remain non-stressed, which can significantly improve the reliability of the textile-embedded wireless components. In this article, we describe fabrication of two-part stretchable and non-stretchable passive ultra-high frequency radio frequency identification textile tags using electro-textile and embroidered antennas, and test their reliability when immersed as well as under cyclic strain. The results are compared to tags with traditional one-part dipole antennas fabricated from electro-textiles and by embroidery. Based on the results achieved, the initial read ranges of the two-part antenna tags, around 5 m, were only slightly shorter than those of the one-part antenna tags. In addition, the tag with two-part antennas can maintain high performance in a moist environment and during continuous stretching, unlike the one-part antenna tag where the antenna-integrated circuit attachment is under stress.


2017 ◽  
Vol 29 (47) ◽  
pp. 1770338 ◽  
Author(s):  
Nicholas R. Glavin ◽  
Kelson D. Chabak ◽  
Eric R. Heller ◽  
Elizabeth A. Moore ◽  
Timothy A. Prusnick ◽  
...  

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