LOOP FILTER WITH COMMUTATION OF THE BREAK OF THE PLL SYSTEM OF THE FREQUENCY SYNTHESIZER (OPTIONS) Russian patent published in 2019 - IPC H03L7/183 H03L7/107 

FIELD: radio engineering.

SUBSTANCE: invention relates to the radio engineering. Achievement of the technical result occurs due to a change in the bandwidth of the loop filter of the PLL by switching RC circuits with different time constants in the feedback circuit of the operational amplifier of the loop filter with fast recharging of capacitors. For this purpose, an input and output corrective RC circuits, an additional capacitor connected to the corresponding output of the second controlled key, are entered in the loop filter, as well as n output RC circuits. In addition, one of the contacts of the first controlled switch is connected to a voltage source and a non-inverted input of the operational amplifier, in parallel with which two RC circuits with a small and a large time constant are connected, respectively.

EFFECT: technical result is to provide high speed synthesizer frequency when changing the output frequency due to the mode of wide bandwidth and reducing the level of phase noise due to the mode of narrow bandwidth in the steady state of the PLL.

4 cl, 4 dwg