UWB in-body channel performance by using a direct antenna designing procedure

UWB systems have been proposed as a candidate for the next generation of in-body applications. In order to perform reliable UWB channel measurements, implantable antennas should work in the propagation medium properly. To assess the UWB channel performance, in-body antenna matching should be assured. Besides, an omnidirectional radiation pattern in order to communicate with a sensor array located around the body should be achieved. This paper is devoted to the analysis of the UWB in-body channel when using an antenna miniaturization procedure that maintains its omnidirectional radiation pattern as well as its operation bandwidth. For that, an UWB monopole antenna with circular patch is directly miniaturized and optimized considering the human muscle tissue. To assess the impact of antenna miniaturization, the results of the channel propagation measurement campaign obtained with the miniaturized antenna are compared with those obtained from a larger UWB monopole in a previous measurement campaign.