An ultrathin wideband capsule antenna with low level specific absorption ratio

In this paper, a miniaturization antenna with stable impedance matching for Wireless capsule endoscope over 1.4GHz Wireless Medical Telemetry Services (WMTS) is proposed only on 0.05mm flexible substrate. In order to achieve impendence matching, inversed T matching branch is employed. Moreover, current vector alignment and conductor coupling factors are used to decrease antenna effective dimensions. Fresh pork is applied to simulation the human body in practice. The input impendence, gain, bandwidth, radiator efficient, SAR value are discussed in detail. Communication links between the proposed and external receiving antennas in different orientations and distance are measured. Simulation and measurement results show that the conformal antenna has a maximum simulated gain of −26.3 dBi (homogeneous muscle) and a minimum gain of −38.57 dBi (small intestine). The maximum impedance bandwidth is 111MHz (7.9%) in a homogeneous muscle phantom.