The invention discloses a self-correcting phaselocked loop
frequency synthesizer capable of realizing
frequency band selection, composed of a phaselocked loop and a self-correction loop; wherein the phaselocked loop is formed by connecting a phase detection
discriminator, a
charge pump, a
loop filter, a
voltage-controlled oscillator and a
frequency divider in sequence, the self-correcting loop is formed by connecting a phase detection
discriminator, a trigger, a controller, a
voltage-controlled oscillator and a
frequency divider in sequence, and the phaselocked loop and the self-correcting loop share the same phase detection
discriminator, the same
voltage-controlled oscillator and the same
frequency divider. The invention realizes
center frequency correction by regulating one group of
fixed capacitor of voltage-controlled oscillator, so that widen frequency tuning range can be obtained under lower
gain of voltage-controlled oscillator, thus error caused by making process of integrated
inductance and variable varactor can be compensated,
phase noise of phaselocked loop
frequency synthesizer is reduced, and implementation of
single chip phaselocked loop
frequency synthesizer by adopting
CMOS technology can be realized.