Key technologies of frequency -hopping frequency synthesizer for Bluetooth RF front-end

摘要

A scheme of a frequency-hopping frequency-synthesizer applied to a Bluetooth ratio frequency (RF) front-end is presented, and design of a voltage controlled oscillator (VCO) and dual-modulus prescaler are focused on. It is fabricated in a 0.18 mu m mixed-signal CMOS (complementary metal-oxide-semiconductor transistor) process. The power dissipation of VCO is low and a stable performance is gained. The measured phase noise of VCO at 2.4 GHz is less than - 114. 32 dBc/Hz. The structure of the DMP is optimized and a novel D-latch integrated with "OR" logic gate is used. The measured results show that the chip can work well under a 1. 8 V power supply. The power dissipation of the core part in a dual modulus prescaler is only 5. 76 mW. An RMS jitter of 2 ps is measured on the output signal at 118.3 MHz. It is less than 0. 02 percent of the clock period.