Low-frequency Signal Generation in Space Based on the High-frequency Electric Antenna Array and Doppler effect

Abstract Low-frequency signals can be used in target detection and geological exploration, but the large antenna sizes limit their applications. Hence, it is significant to investigate the low-frequency signal generation method based on antennas with appropriate sizes. Different from mechanical antenna methods, previous work of this paper proposes a novel low-frequency signal generation method in space on the basis of Doppler effect, and designs the high-frequency electric antenna staggered array and timing sequency of the periodic pulse train signal. In this paper, 8-element short-array and 64-element long-array experimental prototypes are proposed, and the 121.35 MHz signal is composed of 156 MHz radiating element signals. Experimental results show that the measured composite signal spectrums are similar to the simulations and physically verify the feasibility of the low-frequency signal generation method based on the high-frequency electric antenna array, which is valuable in the area of low-frequency signal generation with small antennas.