DESIGN OF A FULLY INTEGRATED 2.4 GHz FREQUENCY PLL SYNTHESIZER FOR ZigBee TRANSCEIVER APPLICATION

摘要

A 2.4-GHz fully integrated frequency synthesizer is presented in this paper for Low-IF ZigBee (IEEE802.15.4) transceiver applications. The frequency synthesizer meets the system requirement of 2.4-2.4835 GHz frequency range with a frequency resolution of 5 MHz. The automatic-amplitude control (AAC) technique is employed for the voltage-controlled oscillator (VCO) which helps to optimize the output amplitude of the VCO over voltage, process and temperature variations. The chip has been fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS) process using a single poly layer, four metal layers and metal-insulator-metal (MIM) capacitors. The synthesized has a current dissipation of 4.7 mA from a 1.8 V power supply and occupies an area of 1 mm~2 × 0.85 mm~2. Measurement results show that the phase noise are -82 dBc/Hz-100 kHz offset and -109 dBc/Hz-1 MHz offset respectively.