Antenna Sensors in Passive Wireless Sensing Systems

Abstract

Antenna sensors have received considerable interests in recent years due to their passive wireless operation, simple configuration, compact size, multiplexing capability, and multimodality sensitivity. Based on the principle of antenna backscattering, an antenna sensor can be wirelessly interrogated at middle range distances without an onboard battery. Since the antenna serves the dual function of sensing and communicating, an antenna sensor can be implemented with minimum number of components. As narrowband resonators, antenna sensors can be easily multiplexed based on the principle of frequency division multiplexing. In addition, different types of antenna sensors that are sensitive to a variety of physical measurands have been demonstrated. Due to these unique features, antenna sensor technology could play a vital role in our drive toward ubiquitous sensing. This chapter provides a comprehensive review of this exciting technology with detailed descriptions on the operational principle and wireless interrogation of batteryless antenna sensors. Four application examples of using antenna sensors for moisture, dynamic strain, temperature, and crack sensing are discussed. Future research directions and open problems are suggested.

UHF RFID Tag Antenna-Based Sensing for Corrosion Detection & Characterization Using Principal Component Analysis

“…Moreover, a dual-resonant (TM01 and TM10 modes) microstrip antenna was proposed to detect the orientation of cracks and demonstrated that its sensivity was related to the relative permittivity and geometrical length [22]. Further information about TABS can be found in [23].…”

Spin Wave Electromagnetic Nano‐Antenna Enabled by Tripartite Phonon‐Magnon‐Photon Coupling

“…At any frequency, the quantity P t = (1− r ) mW, where r is the reflection coefficient calculated from the parameter S 11 (see Supporting Information) at that frequency. We define the “radiation efficiency” as η = G t / D , [ 19 ] where D is the directivity. The antenna is omnidirectional (we do not observe any significant directional dependence of the radiation) which is expected since the antenna dimension is much smaller than the wavelength [ 20 ] and hence the antenna approximates a point source that radiates equally in all directions (isotropic radiator).…”