Ground Testing of the VLF Antenna in the Prototype Spaceborne Plasma Sounding System

In response to the need for detecting the plasma environment within the inner magnetospheric region, Nanchang University has developed a prototype of a spaceborne radio plasma sounding (SRPS) system. One of the core systems of the prototype is the antenna system, which operates in a frequency range of 30 kHz to 3 MHz and includes a 240-meter-long satellite-borne very low frequency(VLF) broadband dipole antenna. However, unlike the space environment, the performance of large antennas can be affected by ground coupling. To test the performance of this antenna on the ground, a drone-suspended 120-meter monopole antenna and a horizontal low-frame 240-meter dipole antenna system were designed and fabricated. The antenna performance, especially in the very low frequency band, was tested through long-distance signal transmission and reception experiments, ionospheric vertical sounding experiments, and ionospheric oblique sounding experiments. The test results show that the antenna has good performance in the broadband operating range. This work can provide a reference for the design and ground testing of miniaturized satellite-borne very low frequency broadband antennas.