An Experimental Study of Electrodes for Through-The-Earth 350 kHz MF Communication

This paper proposes an experimental investigation of electrodes for Medium Frequency (MF) communication Through-The-Earth (TTE) at an operating frequency of 350 kHz. The electrodes are spiked into the ground at the end of each earth-grounded antenna lead. The experiment includes a transmitter system and a receiver system, and the received signal power, conductivity, and impedance are measured using a spectrum analyzer and an LCR meter when the type and number of electrodes are varied. The results show that different electrode types impact conductance and impedance, with higher conductivity and lower impedance electrodes receiving greater signal power compared to other electrodes. Moreover, increasing the number of electrodes enhances the system's ability to receive higher signal power due to improved conductivity and lower impedance, bringing it closer to the impedance of the radio transceiver. These are the importance of selecting suitable electrode types and numbers for optimal signal transmission and receiving in TTE communication at 350 kHz.