Calculation of Interference Spectrum in Frequency Synthesizers Split Mismatch Charging Pump Currents

Relations for calculation of interference spectra in the system of pulse-phase automatic frequency adjustment (pulse PLL) with fractional frequency dividers using delta-sigma modulation and pulse-phase detector with non-identical pumping currents are obtained. Based on the obtained ratios, a program has been developed to calculate the level of fragmentation interference. The calculated values of fractional interference are compared with the results of pulse PLL simulation with fractional divisors in the SIMULINK subsystem of MATLAB.