Small Electrical Antenna for SAW Sensor Biotelemetry

A spiral antenna matched to a SAW sensor for blood pressure and body temperature monitoring is proposed. As the antenna/SAW device is dedicated to be implanted in a human body, a small antenna with omnidirectional pattern is required. The proposed structure has a total area of 4 × 2.5 mm2 and a 1.1 mm height. To take into account the human body effect, we use a homogenous phantom with a dielectric permittivity of 52 and a conductivity of 1.74 S/m. The −10 dB impedance bandwidth of the proposed antenna is 66% from 2.22 to 3.83 GHz; moreover, a quasi‐isotropic radiation pattern is achieved.