In this paper, an implantable antenna with a semi‐circular slotted patch and a Z‐shaped slotted defective ground structure antenna for biotelemetry applications have been proposed. The antenna resonates at WMTS and ISM bands of 1.42 and 2.42 GHz, respectively. The antenna is compact in size with dimensions of 8 × 9 × 0.635 mm3. To validate the semi‐circular dual band antenna structure, the optimized design is fabricated on Rogers RT/duroid 6010 high dielectric substrate material. The same substrate material is adopted as the superstrate. The experiment was carried out in skin mimicking gel for both WMTS and ISM frequency bands. The designed semi‐circular slotted antenna has peak gain values of −20 dBi, at 2.42 GHz. The observed front‐to‐back ratio at the ISM band is 15.8 dB. The maximum specific absorption rate computed is within safe limits and meets IEEE safety criteria.

A dual‐band bio‐implantable compact antenna with a meander‐line structure is presented. The proposed meander‐line antenna resonates at the industrial, scientific, and medical (2.4 GHz) and wireless medical telemetry (1.4 GHz) bands. The meander‐line structure is selected as a radiating patch given its versatile and effective design. With a dimension of only , the designed antenna is compact. Considering a skin phantom, the proposed antenna was designed, optimized, and simulated. The Rogers RT/duroid 6010 substrate material with high dielectric constant was used to fabricate the meander‐line dual‐band implantable antenna, which was validated experimentally. The superstrate was made of the same material. Experiments were conducted on skin‐mimicking gel. The designed meander‐line antenna has a high peak gain of −21 dBi at 2.4 GHz, and its maximum specific absorption rate is compliant with IEEE safety standards.

Summary A novel fractal‐shaped wideband multiple‐input multiple‐output (MIMO) antenna is proposed for brain and skin implantable applications. This antenna works in the 2.4–2.48 GHz band of industrial, scientific, and medical (ISM) standards. The fractal‐shaped wideband MIMO antenna is miniature in size with a footprint of 0.25em0.13normalλ×0.06normalλ×0.01normalλ. Rogers RT/Duroid 6010 high‐dielectric substrate material is used to fabricate the optimized design in order to validate the implantable MIMO antenna structure. The same high‐permittivity substrate material has been used as a superstrate. Experiments were carried out in brain and skin‐mimicking gel at 2.45 GHz in the ISM band. The proposed antenna has a peak gain of −21.3 dBi at 2.45 GHz. High isolation (>20 dB) between two MIMO ports is attained. The proposed antenna achieves a fractional bandwidth of 36.76% and an impedance bandwidth of 1.02 GHz. According to IEEE safety regulations for 1‐ and 10‐g tissues, the computed maximum specific absorption rate (SAR) is safe bound.