The Difference Analysis on the Effect of Third-Order Intermodulation Between Single Antenna and Antenna Arrays Anti-jamming

Abstract

The time domain and frequency domain anti-jamming technology based on single antenna, and the space domain anti-jamming technology based on antenna arrays, which can realize the interference suppression under the different interference bandwidth. The interference intermodulation would be generated in single antenna and antenna arrays, and the most obvious is the third-order intermodulation. The essence of interference suppression is to zero the interference spectrum in single antenna anti-jamming. When the third-order intermodulation is submerged under the noise, the intermodulation has little effect on frequency domain anti-jamming. However, in the application of antenna arrays anti-jamming, the nature of anti-jamming is to achieve interference cancellation by amplitude and phase weighting, and the consistency between different elements are emphasized. If the non-linear characteristics are the same in different elements, the third-order intermodulation can still be achieve cancellation through the amplitude and phase weighting. Therefore, in antenna array, the anti-jamming performance is not affected by third-order intermodulation on single channel but the non-linear consistency. In this paper, the difference effects on single antenna and antenna arrays of the third order intermodulation are analyzed. Aim to the relationship between interference and intermodulation, a part of the third-order intermodulation could be suppressed, and the suppression method is proposed. The simulation results show that the effectiveness of the analysis and the proposed method.