X-Shaped Slotted Patch Biomedical Implantable Antenna for Wireless Communication Networks

Abstract

Biomedical implantable antennas have a major role in biomedical telemetry applications. Therefore, a compact-size low-profile implantable antenna working in industrial, scientific, and medical (ISM) band at 915 MHz is presented. The presented antenna is a simple slotted patch fed with a coaxial probe of 50 Ω impedance. The patch consists of four slotted resonators printed on a flexible Roger Duroid RT5880 substrate ( ε r = 2.2 , tan δ = 0.0009 ) with the standard thickness of 0.254 mm. The complete volume of the designed antenna is 7 mm × 7 mm × 0.254 mm ( 0.08 λ g × 0.08 λ g × 0.003 λ g ). The antenna covers the bandwidth from 800 MHz to 1 GHz (200 MHz) inside skin tissue. A good agreement between the simulation and measurements of the antenna has been obtained. Finally, the specific absorption rate (SAR) values have also been analyzed through simulations as 8.17 W/kg inside skin over 1 g of mass tissue. The proposed SAR values are less than the limit of the Federal Communications Commission (FCC). This antenna is miniaturized and an ideal applicant for applications in biomedical implants.

A Wideband Bear-Shaped Compact Size Implantable Antenna for In-Body Communications

“…In Ref. [7], the authors presented the compact X-shaped slotted patch antenna of a size of 7 × 7 mm 2 , but the bandwidth achieved from the antennas was 21.85%, which was less than our proposed design in this paper, and the shape of the design was not as novel compared to our proposed design. Since it is not easy to achieve high bandwidth with compact size, our proposed design therefore has attained the wide bandwidth of 25.13%.…”

“…The electromagnetic waves may pose a health risk to humans, and these hazards are determined by means of Sthe AR. The following is the relation between the input power and SAR [7][8][9][10]:…”

“…Since it is not easy to achieve high bandwidth with compact size, our proposed design therefore has attained the wide bandwidth of 25.13%. In the mid-radio range (402-405 MHz) [7][8][9][10] and the ISM band (2.4-2.48 GHz) [11][12][13][14][15][16], several implanted antennas have been stated for this wireless application. Ref.…”

Single-fed broadband CPW-fed circularly polarized implantable antenna for sensing medical applications

“…The following equation describes the link between input power and SAR [ 10 ]: where ‘ σ ’ and ‘ ρ ’ the thermal conductivity (S/m), mass density (kg/m 3 ), and electric field intensity (V/m) are denoted by S and E, respectively. According to below [ 13 ], the electric power intensity is inversely proportional to the signal power.…”

“…A biocompatible CP antenna that can be used on the human body is challenging to construct since the tissues have varying dielectric characteristics. Many in-body CP antennas are created for wireless communication between (402-405 MHz) [6][7][8][9][10][11][12] and (2.4-2.48 GHz) [13][14][15][16][17][18] in the mid radio band range. Biomedical implants may now make use of a small, broadband antenna operating in the MICS band (403 MHz).…”