Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

This article presents a microwave sensor for dielectric characterization and thickness measurement of solid materials. The proposed sensor incorporates an interdigital capacitor (IDC) and a split-ring resonator to create an intense electric field, allowing it to efficiently interact with a sensing material. IDC parameters such as width and gap of the finger and length and gap of the electrode are optimized to enhance the material characterization sensitivity. The microwave resonant sensor structure is designed to operate at 1.8 GHz, making it applicable to measure permittivity and thickness of solid materials. The proximity of the material to be sensed influences the field distribution of the developed sensor, which, in turn, enables the simultaneous measurement of permittivity and thickness based on variations in a resonant frequency. Experimental results reveal that the highest sensitivity value reaches 113.4 MHz/mm and 47.6 MHz/Δε r for permittivity of the solids, when the thickness is between 0 and 1 mm. Furthermore, the developed sensor demonstrates a high accuracy (99.6%) and adequate accuracy (87.6%) for both real and imaginary permittivity, respectively. The developed microwave resonant sensor also shows excellent resolution for permittivity (0.04716) and thickness (0.1314), validating its high-performance for measuring permittivity and thickness for various solids.

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“…The total capacitance is the combination of C MUT and capacitance produced by IDC is calculated from the following Equation ( 1) and (2). 20,21…”

Section: Operation Principle and Design Simulationmentioning

confidence: 99%

Simultaneous measurement of thickness and permittivity using microwave resonator‐based planar sensor

Ali

Wang

Meng

et al. 2021

Int J RF Microw Comput Aided Eng

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“…This review shows the recent development of various studies and examples of applications of microwave planar sensors in material characterization. It includes the mathematical models for complex permittivity extraction [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ], sensing application examples of microwave sensors [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , …”

Section: Introductionmentioning

confidence: 99%

Review of Recent Microwave Planar Resonator-Based Sensors: Techniques of Complex Permittivity Extraction, Applications, Open Challenges and Future Research Directions

Alahnomi

Zakaria

Yussof

et al. 2021

Sensors

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Recent developments in the field of microwave planar sensors have led to a renewed interest in industrial, chemical, biological and medical applications that are capable of performing real-time and non-invasive measurement of material properties. Among the plausible advantages of microwave planar sensors is that they have a compact size, a low cost and the ease of fabrication and integration compared to prevailing sensors. However, some of their main drawbacks can be considered that restrict their usage and limit the range of applications such as their sensitivity and selectivity. The development of high-sensitivity microwave planar sensors is required for highly accurate complex permittivity measurements to monitor the small variations among different material samples. Therefore, the purpose of this paper is to review recent research on the development of microwave planar sensors and further challenges of their sensitivity and selectivity. Furthermore, the techniques of the complex permittivity extraction (real and imaginary parts) are discussed based on the different approaches of mathematical models. The outcomes of this review may facilitate improvements of and an alternative solution for the enhancement of microwave planar sensors’ normalized sensitivity for material characterization, especially in biochemical and beverage industry applications.

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“…IDC has been widely implemented as a passive lumped element in microwave integrated circuits [32]. Porwal et al [33] implements RF sensor by integrating a Spiral Resonator (SR) and an IDC on main microstrip line for GHz operating frequency range. This technique has also been extensively applied in lower MHz frequencies [34], [35].…”

Section: Introductionmentioning

confidence: 99%

Printed Spiral Resonator for Displacement-Tolerant Near-Field Wireless Energy Transfer

et al. 2019

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Synthesis between the printed spiral coil and the planar interdigital capacitor for near-field wireless energy transfer (WET) is proposed. The proposed amalgamated design is intentionally positioned under several displacements, namely, planar offsets at the z-axis as well as lateral offsets at both the x-and y-axes to investigate tolerance capability. This is particularly crucial in practical circumstances, whereby a perfect alignment between primary and secondary resonators is not usually achieved unless with the integration of magnet plates to aid seamless position latching, otherwise complex adaptive matching circuits are needed to compensate for displacements. At a fixed axial transfer distance of 25 mm, the corresponding maximum simulated and measured transfer efficiency is 73.01% and 71.84%, respectively, under perfect alignment. Sustainable power transfer efficiency (PTE) is demonstrated during a 360 • planar clockwise rotation with the step size of 45 • and the measured variation ratio is 0.02 while the feasibility of preserving PTE until 0.6 quotients of lateral displacement and axial distance is validated when up to 15-mm lateral offsets occur either from x or y reference planes. It can thus be concluded that the printed spiral resonator proposed appears to be a good candidate to rectify planar and lateral displacements featuring simplicity and space-saving robust structure that necessitates only a minimized footprint, thus paving the way for adaptation in WET applications, such as consumer electronics and implanted medical devices.

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Design of Rf Sensor for Simultaneous Detection of Complex Permeability and Permittivity of Unknown Sample

Cited by 10 publications

References 30 publications

Simultaneous measurement of thickness and permittivity using microwave resonator‐based planar sensor

Simultaneous measurement of thickness and permittivity using microwave resonator‐based planar sensor

Review of Recent Microwave Planar Resonator-Based Sensors: Techniques of Complex Permittivity Extraction, Applications, Open Challenges and Future Research Directions

Printed Spiral Resonator for Displacement-Tolerant Near-Field Wireless Energy Transfer

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