Receiving system linearity requirements for HF radar

The sensitivity and consequent detection capability of an HF radar should not be compromised by nonlinearities occurring within the receiving systems. Two forms of nonlinear effects, known as intermodulation distortion and cross-modulation distortion, have the potential to limit radar sensitivity. An analysis showing that intermodulation distortion has the greater propensity to limit radar performance for a given large signal and noise environment is given. Further analysis is used to establish a quantitative relationship between the required third-order intercept point and relevant environmental and radar parameters. Adherence to this relationship in the design of an HF radar will ensure its desired immunity to nonlinear effects