Low power and low phase noise 5.7 GHz LC VCO in OOK transmitter for neurosensory application

A 5.7 GHz fully integrated complementary LC voltage controlled oscillator (CLC VCO) has been designed in an inexpensive 0.25-/spl mu/m digital CMOS process for low power neurosensory application. Consuming only 2mA of current from a 2.5 V power supply, the CLC VCO achieves a measured single-sideband phase noise of -92.75 dBc/Hz and -97.6 dBc/Hz at 600 KHz and 1.0 MHz offset frequency, respectively. The CLC VCO is able to output -5dBm of power at the single-ended output to a 50-Ohm load to meet demands of high-date rate short reach on-off keying (OOK) wireless transmission. Various low power techniques used to improve phase noise in the LC VCO are also discussed.