A 4.8 GHz RF CMOS wideband LC VCO for wireless sensor networks RFICs

A 4.8 GHz LC voltage controlled oscillator (VCO) for Wireless Sensor Network (WSN) SoC RFIC chipset is designed based on SMIC 0.18 ¿m 1P6M RF CMOS process. The core circuit adopts complementary differential negative resistance structure with resistor biasing which achieves good phase noise performance. The 2 bit switched capacitor array provides extra tuning range. The chip size is 600 ¿m × 475 ¿m with testing pads. With a 1.8 V supply voltage, the post-simulation and chipset measured results show that the achieved maximum 40% tuning range can perfectly compensating the deviation due to process corners. And the measured phase noise is -96 dBc/Hz@3 MHz with the carrier be 4.8 GHz. Besides, the operating current of the whole circuit is less than 7 mA.