Varshney, AtulGencoglan, Duygu Nazan2026-02-272026-02-2720252193-567X2191-428110.1007/s13369-025-10396-3http://dx.doi.org/10.1007/s13369-025-10396-3https://hdl.handle.net/20.500.14669/4500This paper presents a novel, compact, bioinspired spider-shaped reconfigurable antenna designed for multi-band wireless applications spanning the S-band, C-band, 5G sub-6 GHz, and emerging 6G bands (7.125-8.40 GHz). Recent frequency-reconfigurable antennas often rely on multiple PIN diodes, stacked substrates, or complex tuning networks, leading to increased size, cost, and fabrication complexity. Many designs also prioritize frequency tunability while overlooking gain enhancement, limiting their effectiveness in long-range, high-data-rate scenarios. Furthermore, most reported antennas do not address the critical intermediate 6G band (7.125-8.40 GHz), and high-performance designs commonly use costly substrates like Rogers RT5880, making them unsuitable for mass deployment. The key challenges faced in designing this include maintaining radiation efficiency in a miniaturized spider-shaped geometry, achieving stable ON/OFF switching with a single PIN diode (BAR64-02V), mitigating dielectric dispersion losses on FR-4 at higher frequencies, and ensuring reliable multi-band operation in a low-cost structure. To address these issues, a novel slotted-fractal and filleted design (developed from a circular patch to a spider-shaped) antenna was fabricated on an FR-4 substrate. The antenna dynamically tunes frequency and gain by controlling current paths via a single RF switch. In measurements, it achieves 4.64 dBi gain at 3.58 GHz (no diode), enhanced to 9.03 dBi in the diode's ON state, and doubles the upper-band bandwidth from 1.43 to 2.86 GHz in the OFF state. The design realizes a 43.25% size reduction and exhibits excellent agreement between measured and simulated performance, offering a cost-effective and scalable solution for future wireless systems.eninfo:eu-repo/semantics/closedAccessBioinspiredFrequency and gain reconfigurableMulti-bandSub-6 GHzNew 6G bandArticle; Early AccessWOS:001524612800001