Statistical Preprocessing and Boxplot-Based Analysis of Multiband Microwave Absorption Performance in Single-Slot Pyramidal Microwave Absorbers

DOI

10.2991/978-94-6239-745-3_23How to use a DOI?

Keywords

microwave absorber; multiband; boxplot analysis; pyramidal absorber; outlier removal; IQR method

Abstract

This paper presents a statistical preprocessing and boxplot analysis of microwave absorption performance for single-slot pyramidal microwave absorbers operating in L-band, S-band, C-band, and X-band frequency ranges. The absorbers were fabricated using biomass-derived carbon coating material as part of a sustainable microwave absorber design and configured with three slot sizes, namely big, medium, and small. More than 1200 experimental absorption data points were collected from multiple frequency measurements for each band to enable statistical evaluation of multiband absorption behaviour. Boxplot analysis was performed to visualize the distribution of absorption values for different slot sizes and frequency bands. The initial dataset contained 29, 57, 114, and 201 data points for L, S, C, and X band respectively for each slot configuration. The analysis revealed the presence of extreme values that could affect the reliability of interpretation. Therefore, outlier removal was applied using the interquartile range (IQR) method with a multiplier of 1.5. After preprocessing, the number of data points was reduced to 25 for L-band, 54 for S-band, 103 for C-band, and 194 for X-band depending on slot size. The results show that lower frequency bands produce more stable absorption performance, while higher frequency bands, especially C-band and X-band, exhibit larger variation with absorption values below −40 dB. Slot size also influences stability, where the small slot shows wider distribution compared to the big slot. The study confirms that boxplot analysis with IQR-based outlier removal provides a reliable and effective approach for evaluating multiband microwave absorption data obtained from experimental measurements of sustainable pyramidal microwave absorbers.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits any noncommercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if you modified the licensed material. You do not have permission under this license to share adapted material derived from this chapter or parts of it.

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TY  - CONF
AU  - Yaakub Omar
AU  - Ilya Ismail
AU  - Nur Athirah Syafiqah Noramli
AU  - Nurlaila Ismail
AU  - Hasnain Abdullah
AU  - Mohd Nasir Taib
PY  - 2026
DA  - 2026/08/24
TI  - Statistical Preprocessing and Boxplot-Based Analysis of Multiband Microwave Absorption Performance in Single-Slot Pyramidal Microwave Absorbers
BT  - Proceedings of the International Conference on Research, Innovation, Sustainability, and Educations (IRISECON 2026)
PB  - Atlantis Press
SP  - 350
EP  - 363
SN  - 3091-4442
UR  - https://doi.org/10.2991/978-94-6239-745-3_23
DO  - 10.2991/978-94-6239-745-3_23
ID  - Omar2026
ER  -