A compact reader for wireless passive sensors
Abstract/Contents
- Abstract
- The demand for continuous, long-term wireless sensing is growing in applications where tethered links cannot be used. Achieving a complete sensing solution requires innovations both in the reader and the sensor to make them easy-to-manufacture, small, safe, disposable, and yet sufficiently functional. Fully passive sensors (FPS) which consist of only a resistive-capacitive-inductive (RLC) tank are widely used as a simple and inexpensive alternative to their active counterparts. Although great effort and progress have been made in developing such sensors, the reader design remains a bottleneck. Existing solutions rely on forced excitation which makes the implementation inherently more complex. Self-oscillation circumvents these limitations. We show that a nonlinear negative resistance which exhibits a step-like current-voltage characteristic enables self-oscillation to automatically find and lock to the sensor value. Moreover, use of a non-resonant reader coil or unidentical tank topologies in the reader and sensor results in distance dependency of measurement results. We investigate the sources of distance variations and suppress their effects by optimizing the tank topology and employing a closed-loop mechanism which locks to the point of operation with minimum variation. Both improvements allow for a simple reader sticker (5.4cm by 3.4cm) which is wirelessly powered using near-field communication signals and achieves < 0.16% variation over a distance of 1.6cm for a 1.2kOhm sensor resistance. This simple reader solution advances the field of continuous, ubiquitous, and long-term sensing, paving the way for widespread deployment in daily applications, such as food safety, structural, and health monitoring.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Kananian, Siavash |
|---|---|
| Degree supervisor | Poon, Ada Shuk Yan |
| Thesis advisor | Poon, Ada Shuk Yan |
| Thesis advisor | Emami-Naeini, Abbas |
| Thesis advisor | Howe, Roger Thomas |
| Degree committee member | Emami-Naeini, Abbas |
| Degree committee member | Howe, Roger Thomas |
| Associated with | Stanford University, Department of Electrical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Siavash Kananian. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/dp324mj8170 |
Access conditions
- Copyright
- © 2022 by Siavash Kananian
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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