Distortion of the Radiation Pattern of the «Array-Receiver» System Exposed to Fast and Slow Multiplicative Noise

The concept of the radiation pattern of the array-receiver system is given; the expressions are obtained in the absence and presence of multiplicative (modulating) noise. The effect of noise on the system is described by averaging the instantaneous radiation pattern over a time interval equal to the signal duration. The influence of periodic, fast and slow fluctuation noise on the distortion of the radiation pattern is described. With the same width of the signal spectrum and other equal conditions, the distortion of the pattern when using unmodulated pulse signals is significantly greater than when using signals with intra-pulse modulation. The degree of distortion reduction associated with the smoothing effect of the matched filter of the receiver depends on the ratio between the spectrum width of the noise modulation function and the bandwidth in which the autocorrelation function of the signal is significantly different from zero. An example of the effect of phase distortions with normal distribution on arrays with phase shifters is considered.