On the design and analysis of multi-band micro-strip patch antenna for wireless body area network applications

Gopinath and Marichamy J Wireless Com Network (2025) 2025:13 https://doi.org/10.1186/s13638-025-02442-3 EURASIP Journal on Wireless Communications and Networking Open Access RESEARCH On the design and analysis of multi‑band micro‑strip patch antenna for wireless body area network applications D. Gopinath1* and P. Marichamy2 *Correspondence: 1 Department of Electronics and Communications Engineering, Ramco Institute of Technology, Rajapalayam, Tamilnadu 626117, India 2 Department of Electronics and Communications Engineering, P.S.R. Engineering College, Sivakasi, Tamilnadu 626140, India Abstract The Microstrip patch antenna has applications in several areas in today’s world. In this article, a detailed design and investigation report of multi-band microstrip patch antenna for the WBAN applications is presented. In this design, the Flame Retardant-4 (FR-4) substrate is placed in between the top radiator and the ground plane. The physical size of the patch is 38 × 29.4 mm. There are several techniques available to create multiple resonant frequencies. Multi-band can be achieved using the Partial ground plane (PGP) technique, Band Gap structure materials, and by making slots in the patch. In this design, seven resonant frequencies are obtained by making slots in the patch. The optimization process is done by a parametric analysis approach in the Ansys HFSS tool. In this design, resonant frequencies are observed as 1.99, 4.22, 5.04, 5.56, 6.63, 7.57, and 8.07 GHz, which are suitable for S band and C band applications. Reflection Coefficient, Gain, VSWR, and Specific absorption rate (SAR) are measured for each resonating frequency with respect to free space and human phantom model. Antenna parameters were in the acceptable range and this design would work well with WBAN applications. Keywords: Antenna, Slot antenna, Multiband, Specific absorption rate 1 Introduction In the last few decades, antenna has become the primary requirement for modern wireless personal communication devices such as the smartphone. In such devices, the antenna receives and transmits radio electromagnetic waves. An electrical signal is converted into radio waves and is sent to the receiver by the transmitting antenna. The receiving antenna then turns the radio waves back into an electrical signal. There are different antenna techniques which enable multi-band attributes. The advantages of the multi-band antenna are its advanced modulation and low power consumption. Additionally, multi-band antennas assist in minimizing the system’s size and complexity. Although there are several types of antennas, the microstrip patch antenna has several benefits due to its low-profile features and is suitable for compact devices. At the same time, it has some drawbacks such as narrow bandwidth and low gain. This article aims to develop a multi-band microstrip patch antenna that provides sufficient gain suited to WBAN applications. In existing multi-band antennas, crucial factors like gain © The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial 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 licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. Gopinath and Marichamy J Wireless Com Network (2025) 2025:13 and radiation efficiency are below the necessary level. Such antennas also lag in resonating with different frequencies. A multi-band antenna is usually preferred by wireless providers because of its multi-utility and economy. Some of the multi-band techniques are: Slot Loading, Notch Loading, Use of Fractal geometries, Lumped Element Loading, Short Micro Strip Antennas, and Defected ground plane structures (DGS). Multi-band antennas can operate on many bands. These antennas frequently have designs where one portion of the antenna is active on a single frequency while its alternative portion is active on other band. In order to compensate for its average gain, a multi-band antenna might even be larger in size. A patch antenna is a radio antenna with a low-profile that may be installed on a flat surface. Some of the previous research work related to multi-band antenna techniques are discussed below. In [1], a frequency reconfigurable-multi-band antenna was designed using PIN diodes. Here, a flexible coplanar strip was fed into it. The antenna, which used a flexible polyamide substrate, produced a minimum reflection coefficient of − 23.79 dB and a maximum gain of 3.73 dBi for the three resonant frequencies. It is used to make the operation of bluetooth and 5G next generation applications easier. The gain of the antenna was also considerably low. In another research work [2], FR-4 substrate was used in the multi-band patch antenna featuring three perforations that function in tetra resonant frequency bands. These bands were obtained by combining the Coyote Optimization Technique. It was natureinspired meta-heuristic method. The suggested antenna performed well in cellular and long-distance communication applications. The suggested antenna’s measured observations exhibited a maximum gain of 3.94 dBi, which is somewhat low. In [3], The antenna structure had geometric alterations through the incorporation of meticulously designed capacitively-coupled and inductively-loaded components to the primary patch. This was done so that it can radiate efficiently for four resonating frequencies. It used Rogers RO3003 substrate with minimum S11 of − 29 dB and a gain of 8.03 dBi, which is expected to be used in future generations of mobile handsets. In another research work [4], an antenna comprising a complementary split-ring resonator (CSRR) was designed. It was also incorporated with monopole antenna that worked in the frequency bands 2.4–2.5/2.9–4.8/5.1–6.5 GHz. Here, FR-4 substrate was used with S11 of -40 dB and a gain of 5.5 dBi. In [5], Rogers RO3210 substrate was used in the size-reduced multi-band antenna. This antenna was designed for Terahertz application. The antenna operated in resonant frequencies of 0.2, 0.52, and 0.95 THz. Moreover, the upper and lower semi-circular ring aperture was incorporated to get the multi-band with minimum S11 (...truncated)