Small antenna for leads pacemakers

In this study, a miniature leads pacemaker antenna was presented. The antenna is a $19.8 \times 14.85 \times 1.9 \mathrm{mm}^{3}$ patch composed of a ground plane, a copper meander, a Roger RO 3010 type substrate $\left(\varepsilon_{r}=11.2, \tan \delta=0.0022\right)$ and a biocompatible alumina type superstrate $\left(\varepsilon_{\mathrm{r}}=9.9, \tan \delta=0.0001\right)$. The antenna is placed on the top surface of a pacemaker wrapped with the biocompatible alumina. The antenna provides two bandwidths of 214 MHz and 1140 MHz. The resonance modes associated with these bands are respectively at 868 MHz and 1570 MHz with reflection coefficients of −41.55 dB and −22.16 dB. Simulation of the antenna radiation pattern in the elliptical phantom model of a tissue $\left(\varepsilon_{\mathrm{r}}=57, \sigma=0.79\mathrm{S}/\mathrm{m}\right)$ shows that the antenna has a peak gain of −21.9 dBi. The phantom model of $100 \times 100 \times 50 \mathrm{mm}^{3}$ was considered in the simulation. The behavior of the antenna was also studied when it is in the vicinity of internal electronic components of the pacemaker. The result of the simulation in terms of the $S 11$ coefficient shows that the antenna remains well matched despite this unfavorable environment. The realized link assessment also proves that stable and long-range communications (27.81 m at 868 MHz and 32.25 m at 1570 MHz) can be established between a transmitter using the proposed antenna and an Out-Of-Body receiver.