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R. Hema,
S. Subbulakshmi,
N. Noorunnisa,
M. Nagarajan,
M. Sundararajan,
- Associate Professor, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India
- Assistant Professor, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India
- Ph.D Scholar, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India
- Associate Professor, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India
- Vice-Chancellor, Bharath Institute of Higher Education and Research, Chennai,, Tamil Nadu, India
Abstract
Polymer–ceramic composite substrates play a crucial role in determining the electromagnetic performance, mechanical stability, and thermal reliability of radio-frequency devices. In this work, a polymer-based composite substrate is systematically investigated for its suitability in compact IoT and RFID antenna applications. A fractal-structured antenna is employed as a functional test platform to evaluate the dielectric behavior, impedance characteristics, and radiation efficiency of the composite substrate. Novelty of the proposed reader antenna is built on a modified fractal tree structure, where the angle between the two twigs is halved with each iteration. This design allows for a greater electrical length within a fixed physical space, enabling the structure to be miniaturized. The proposed substrate, based on flame-retardant glass-fiber-reinforced epoxy (FR-4), offers a balanced combination of relative permittivity (εᵣ ≈ 4.4), low dielectric loss (tan δ ≈ 0.012), mechanical robustness, and cost-effective manufacturability. The influence of polymer composite thickness, dielectric constant, and loss tangent on antenna bandwidth, gain, and axial-ratio bandwidth is systematically analyzed using electromagnetic simulations (CST Microwave Studio) and experimental validation (Vector Network Analyzer). Results demonstrate that the FR-4 polymer–ceramic composite substrate significantly enhances impedance matching, electrical length, and radiation performance, achieving a peak gain of 5.7 dBi at 3.5 GHz with improved axial-ratio bandwidth (ARBW) of 2.1 GHz. The study highlights the critical role of polymer composite substrate engineering in optimizing RF performance for low-cost, mechanically stable, and thermally reliable IoT and RFID systems. Additionally, the substrate exhibits stable performance under practical fabrication tolerances and environmental conditions, indicating its suitability for mass-produced wireless devices. Comparative analysis with conventional substrates confirms superior trade-offs between performance, cost, and durability. The proposed approach provides valuable design guidelines for integrating polymer–ceramic composite substrates into next-generation compact, broadband, and circularly polarized antennas.
Keywords: Polymer–ceramic composites, FR-4 epoxy substrate, dielectric properties, electromagnetic characterization, IoT devices, RFID substrates, fractal geometry, substrate engineering
R. Hema, S. Subbulakshmi, N. Noorunnisa, M. Nagarajan, M. Sundararajan. Electromagnetic and Dielectric Performance of Polymer–Ceramic Composite Substrates for Fractal-Based IoT-Antenna Fabrication. Journal of Polymer & Composites. 2026; 14(01):-.
R. Hema, S. Subbulakshmi, N. Noorunnisa, M. Nagarajan, M. Sundararajan. Electromagnetic and Dielectric Performance of Polymer–Ceramic Composite Substrates for Fractal-Based IoT-Antenna Fabrication. Journal of Polymer & Composites. 2026; 14(01):-. Available from: https://journals.stmjournals.com/jopc/article=2026/view=236757
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Journal of Polymer & Composites
| Volume | 14 |
| 01 | |
| Received | 26/12/2025 |
| Accepted | 06/02/2026 |
| Published | 12/02/2026 |
| Publication Time | 48 Days |
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