摘要
A 1.2 GHz frequency synthesizer integrated in a RF receiver for Beidou navigation is implemented in standard 0.18μm CMOS technology.A distributed biased varactor LC voltage-controlled oscillator is employed to achieve low tuning sensitivity and optimized phase noise performance.A high-speed and low-switching-noise divider-by-2 circuit based on a source-coupled logic structure is adopted to generate a quadrature（I/Q） local oscillating signal.A high-speed 8/9 dual-modulus prescaler（DMP）,a programmable-delay phase frequency detector without dead-zone problem,and a programmable-current charge pump are also integrated into the frequency synthesizer. The frequency synthesizer demonstrates an output frequency from 1.05 to 1.30 GHz,and the phase noise is-98.53 dBc/Hz at 100-kHz offset and -121.92 dBc/Hz at 1-MHz offset from the carrier frequency of 1.21 GHz. The power dissipation of the core circuits without the output buffer is 9.8 mW from a 1.8 V power supply.The total area of the receiver is 2.4×1.6 mm^2.
A 1.2 GHz frequency synthesizer integrated in a RF receiver for Beidou navigation is implemented in standard 0.18μm CMOS technology.A distributed biased varactor LC voltage-controlled oscillator is employed to achieve low tuning sensitivity and optimized phase noise performance.A high-speed and low-switching-noise divider-by-2 circuit based on a source-coupled logic structure is adopted to generate a quadrature（I/Q） local oscillating signal.A high-speed 8/9 dual-modulus prescaler（DMP）,a programmable-delay phase frequency detector without dead-zone problem,and a programmable-current charge pump are also integrated into the frequency synthesizer. The frequency synthesizer demonstrates an output frequency from 1.05 to 1.30 GHz,and the phase noise is-98.53 dBc/Hz at 100-kHz offset and -121.92 dBc/Hz at 1-MHz offset from the carrier frequency of 1.21 GHz. The power dissipation of the core circuits without the output buffer is 9.8 mW from a 1.8 V power supply.The total area of the receiver is 2.4×1.6 mm^2.
