Combined Antenna-Channel Characterization for Wireless Communication from Horse Hoof to Base Station

This paper presents a design of an antenna in the complex environment of the horse hoof for sub-gigahertz (868 MHz) communication. The influence of the leg and the ground on the performance were examined by means of finite-difference time-domain simulations. Furthermore, an adaptation was presented to increase the efficiency of the antenna. The first device has a center frequency of 858 MHz and a bandwidth of 99.5 MHz. The total efficiency is 3.12%. Adding the ground to the model results in the ground absorbing most of the radiated power which leads to a total efficiency drop to 1.6%. The center frequency stays the same (at 862 MHz). The bandwidth decreases to 70 MHz. When the horseshoe is connected to the device, the antenna is not tuned anymore, yet the the total efficiency stays 3.08%. This shows that connecting the device to the horseshoe leads to better radiation efficiency. When using LoRa technology, this setup can reach 1631 m if the hoof is in the air. When the hoof is on the ground, only a range of 115 m is estimated.