Miniaturization of the Network Analyzer as an Interface Circuit for Wearable Resonance-Based Sensors
Advisory Committee Chair
Mirbozorgi S Abdollah
Advisory Committee Members
Jololian Leon
Haider R Mohammad
Document Type
Thesis
Date of Award
2021
Degree Name by School
Master of Electrical Engineering (MEE) School of Engineering
Abstract
Readout interface circuits are the essential part of all sensor units. Miniaturing such circuits is a challenging design issue for the future of the Internet of Things, wearable and implantable biomedical devices, sensors for harsh environments, etc. For developing wireless telemetry sensors, Vector Network Analyzer (VNA) is a powerful measurement instrument that can measure scattering parameters (S-Parameters) of single and dual-port networks, as well as Y- and Z-parameters. However, VNAs are expensive and bulky and cannot be carried around, and therefore, they can’t be used as a sensor interface. This thesis aims to design, develop, and implement a miniaturized data collection/sensing and processing system, to be replaced by laboratories VNAs, but easy to carry. The proposed design includes S-Parameter sensing interface circuit (similar to VNA), processor unit, and Bluetooth low energy (BLE) transceiver. To operate the proposed hardware, required codes and algorithms (software for the sensing unit’s processor and an App for smartphones) are developed to form a graphical user interface (GUI), compatible with Android devices, and collect data. The proposed design can measure the reflection coefficient (S11) of passive inductive sensors (1 MHz – 50 MHz), digitalize the data, and transfer it to App/GUI unit in a smartphone via BLE. The captured data includes the information of the sensors, including the resonance frequency variations of a passive sensor. The user can monitor the sensor’ data (S11) in real-time. The implemented sensing circuit interface unit has a low power consumption of 300mW. The dimension of the sensing circuit interface unit equals 3 mm X 23 mm X 51 mm (weight:g). The measured resolution of the proposed system is 30 kHz for measuring the changes of the resonances frequency, the proposed sensor unit can sweep the frequency from 1 MHz to 50 MHz within 0.1 s (measured refreshment speed: 10 times per second).
Recommended Citation
Wu, Fan, "Miniaturization of the Network Analyzer as an Interface Circuit for Wearable Resonance-Based Sensors" (2021). All ETDs from UAB. 714.
https://digitalcommons.library.uab.edu/etd-collection/714