Arefin Md Shamsul, Redoute Jean-Michel, Yuce Mehmet Rasit
Annu Int Conf IEEE Eng Med Biol Soc. 2016 Aug;2016:3031-3034. doi: 10.1109/EMBC.2016.7591368.
The wireless capsule has been used to measure physiological parameters in the gastrointestinal tract where communication from in-body to external receiver is necessary using a miniaturized antenna with high gain and onmidirectional radiation pattern. This paper presents a meandered conformal antenna with center frequency of 433 MHz for a wireless link between an in-body capsule system and an ex-body receiver system. The antenna is wrapped around the wireless capsule, which provides extra space for other circuits and sensors inside the capsule as well as allows it having larger dimensions compared to inner antennas. This paper analyses return loss, radiation pattern, antenna gain, and propagation loss using pork as the gastrointestinal tissue simulating medium. From the radiation pattern and return loss results, the antenna shows an omni-directional radiation pattern and an ultrawide bandwidth of 124.4 MHz (371.6 to 496 MHz) for VSWR <; 2. Experimental results shows that the path loss is 17.24 dB for an in-body propagation distance of 140 mm.
无线胶囊已被用于测量胃肠道中的生理参数，在这种情况下，需要使用具有高增益和全向辐射方向图的小型化天线，将体内信号传输到外部接收器。本文提出了一种中心频率为433MHz的曲折共形天线，用于体内胶囊系统与体外接收器系统之间的无线链路。该天线缠绕在无线胶囊周围，这为胶囊内的其他电路和传感器提供了额外空间，并且与内部天线相比，允许其具有更大的尺寸。本文以猪肉作为胃肠道组织模拟介质，分析了回波损耗、辐射方向图、天线增益和传播损耗。从辐射方向图和回波损耗结果来看，该天线呈现全向辐射方向图，对于电压驻波比（VSWR）<2，具有124.4MHz（371.6至496MHz）的超宽带宽。实验结果表明，对于140mm的体内传播距离，路径损耗为17.24dB。
