Combination frequencies in the interaction between high-power short-wave radiation and ionospheric plasma
Getmantsev G.G., Zuikov N.A., Kotik D.S., Mironenko L.F., Mityakov N.A., Rapoport V.O., Sazonov Yu.A., Trakhtengerts V.Yu., Eidman V.Ya.
Emission due to quadratic nonlinearity in the ionosphere was observed at the modulation frequency of a high-power short-wave transmitter. The transmitter delivered an average power of 130 kW at 5.75 MHz to an antenna with a vertical directivity pattern. The antenna gain was G=;150. A signal with field intensity Ε —0.02 μν/m was registered in daytime at transmitter modulation frequencies from 1.2 to 7 kHz at a distance 180 km. It is shown that the principal role in the formation of the combination-frequency signals is played by the heating nonlinearity in the ionosphere D layer.