Estimating antenna coupling factor for problem of topside ionosphere sounding from space by chirp signals

When developing the first topside ionosphere sounding stations, the issue was debated concerning the improvement of the electromagnetic compatibility of these stations through the use of chirp signals. One of the main problems of using chirp signals was the impossibility of ensuring simultaneous operation of receiver and transmitter. The article presents the results of the use of receiving and transmitting dipole antennas for sounding the ionosphere by a chirp signal, which have a common center. Conclusions are drawn about the possibility of using such facilities for sounding the external ionosphere with hardware separation of polarizations and in the terrestrial version with orthogonal location of receiving and transmitting antennas. During tests conducted on a specially designed antenna stand, we have found that the coupling factor of transmitting and receiving antennas at mutual angles of 45° is no more than -10 dB, and the difference between coupling factors of transmitting and receiving antennas with mutual angles of 45° and 90° is ~15 dB.