Figure 5

Targeting in vivo applications. The human head model used for the simulations is shown in (a). The inset shows a close up of the helical antenna embedded into a tooth. (b) The frequency dependence of the S₁₁ parameter for the helical antenna (diameter: 350 μm; encapsulated in a polymeric matrix) used as a tooth implant or implanted under the skin. The resonant frequency is shifted down to 2.45 GHz for the tooth implant. (c) The spatial distribution of the electric field of the antenna. (d) The radiation pattern of the antenna (gain of the antenna is plotted). The calculation was performed at 2.45 GHz. (e) Attenuation of the signal transmitted by the antenna to the receiver as a function of the distance between transmitter and receiver. The antenna can communicate up to a distance of 2 m in air. A dipole antenna is used as a receiver. (f) Orthogonal cuts through the center of the helical antenna, revealing the spatial distribution of the specific absorption ratio calculated with respect to 10 g of body tissue. The transmitting power of the helical antenna is 25 μW. The calculation was performed at 2.45 GHz.