High Precision Digital Phase Detecting Method And Its Error Analysis

Phase detecting technology widely used in communication, aerospace, distance, direction,frequency and motor control, and other fields. The researchers in these fields of engineeringapplication studying in the process of design, have to chose a suitable phase method frommany phase detecting methods through the process of the literature and complex calculationprocess. Through the analyzing and comparing several phase detecting methods，this articleprovides reference of phase detecting method on the basis of more convenient choice forphase researchers in the field of engineering application.Due to the cost, complexity and precision of phase, etc., digital phase detecting methodhave the great advantage. Therefore, this paper compares several common methods of digitalphase detecting. In digital phase detecting method, A/D sampling process has a veryimportant influence on phase noise. So firstly, this paper analyzes the factors which have aninfluence on the phase noise of the signal waiting to detect through the A/D sampling.Through MATLAB simulation, this paper analyzed the quantization precision, the clock jitterand the sampling frequency in the process of sampling which have influences on the phasenoise SNR. Then according to the phase detecting in the engineering application, through thesimulation for amplitude, frequency, phase difference and phase noise of the signal waiting todetect, using different methods of digital algorithm phase detecting to detect the signal, thispaper compares the precision of phase detecting with those factors. And this paper alsocompares the precision of phase detecting of these digital algorithm phase detecting methodslength ways.In this paper, by establishing the model and programming, this paper analyzes the commonfactors that affect the precision of phase comparison; and then this paper compares the phasedetecting precision of each of four common digital phase detecting methods. Drawing theconclusion: nowadays, due to the high cost, relatively complex of the circuit, affected by thecircuit components in phase and phase precision low faults, analog phase method is seldomused. Among several common numerical algorithms for the phase detecting method, the all phase FFT phase detecting method have the highest precision. When the amplitude of thesignal waiting to detect is1V, the frequency is5KHZ, the sampling frequency is1800KHZ,the phase noise is80dB SNR, and the sampling points is4096, the maximum phase error isabout0.00045°. And the phase accuracy is increased with the decrease of the phase noise,and with the increase of sampling frequency, and with the increase of sampling frequency.