Research of phase noise of direct digital synthesizers

Abstract

The general expression for approximation of power spectral density (SD) of phase noise direct digital synthesizers. The design procedure of factors of SD approximation of phase noise is developed. Calculated SD for integrated DDS from Analog Devices have shown good coincidence with experimental characteristics.Index Terms -DDS, signal synthesis, phase noise, spectral density.

The regression model of power spectral density of phase noise of direct digital synthesizers

“…5. This values are different from the known [5,6] (k 1 = -8.3, k 2 = -8.93, k 3 = -16.2, k 4 = -13.5). The obtained noise characteristics for DDS AD9956, shown in Fig.…”

“…To represent the power spectral density of phase noise of DDS in [5] proposed the model that is based on the power functions of the form where the coefficients k 1 , k 2 , k 3 , k 4 are define the PSD of 1/F 2 noise, of 1/F noise, of thermal noise of input circuits, of thermal noise of load, respectively; F is frequency offset;…”

“…These models have the necessary accuracy only for a certain class of synthesizers. A more accurate model of the power spectral density of DDS phase noise was obtained in [5] and studied in [6][7][8][9][10][11].…”

Coherent Measurements of a Multistatic MIMO Radar Network With Phase Noise Optimized Non-Coherent Signal Synthesis

“…The phase noise L ,DAC,Out at the output of the DAC consists of the sum of the phase noise of the reference oscillator L ,Ref and the internal phase noise L ,DDS of the DDS circuit and is given by [32]…”

The mathematical model of noise characteristics of a direct digital synthesizer with the built-in multiplier of clock frequency on PLL

“…It is rather difficult to determine the estimated noise level for other coefficients of multiplication and at any values of clock frequency experimentally, as high-precision expensive spectrum analyzers are required It is desirable to have possibility of a theoretical assessment of the phase noise level, using the data of the developers. In [1][2][3][4][5][6] the mathematical models of PSD of phase noise of functional links of systems of PLL, and in [7][8][9][10] similar models of direct digital synthesizer are worked out for these purposes, that gives the chance to estimate noise characteristics almost for the whole wide range of output and clock frequencies.…”