Periodic Phase Modulation Method for Fast Diagnosis of Phased Array

A novel periodic phase modulation method is proposed and verified for the fast diagnosis of phased array. Taking the diagnosis of receiving paths as an example, its principle is as follows. Periodic phase modulations with different frequencies are added to each phase shifter of the phased array. Because of the periodic modulation, harmonic components are generated in all the elements. As modulation frequencies added to all the elements are different from each other, the generated harmonic components have different frequencies correspondingly. If some elements suffer failure, the corresponding harmonic components will vanish from the output of the power combiner. Therefore, the faulty elements can be located by analyzing the spectrum of the received signal after the power combiner. The proposed method needs no the auxiliary hardware and its signal processing is concise. An eight-element S-band phased array is fabricated to examine its effectiveness.