Prediction method of multi-frequency non-intermodulation electromagnetic radiation blocking effect of BeiDou navigation receiver

In the test of the electromagnetic radiation blocking effect of the navigation receiver, it is found that the sensitivity of the navigation receiver to single frequency continuous waves and sinusoidal amplitude modulation waves will change with the change in the satellite useful signal strength. This phenomenon reflects that the sensitivity of frequency equipment to multi-frequency electromagnetic radiation is not fixed to a certain extent. In order to make up for the deficiency that the existing multi-frequency electromagnetic radiation evaluation methods can only deal with a single situation, this paper uses the time delay characteristics of the circuit response, introduces the concepts of normalized interference levels and signal duty cycles, establishes the evaluation model of the multi-frequency non-intermodulation electromagnetic radiation blocking effect of frequency equipment, and puts forward the prediction method of the multi-frequency electromagnetic radiation blocking effect of frequency equipment. Taking a certain type of BeiDou navigation receiver as the test object, the single-frequency continuous wave and double-frequency continuous wave electromagnetic radiation blocking effect tests are carried out by using the full-level irradiation method. The test data are substituted into the model established in this paper for verification. The results show that the maximum evaluation error of the model is 2.23 dB. The model and the effect prediction method established in this paper are of great significance for the survival ability evaluation of frequency equipment in complex electromagnetic environments.