A low power current reused quadrature VCO for biomedical applications

This paper presents a low power current reusing quadrature voltage controlled oscillator for use in implantable electronics operating in the 402 MHz to 405 MHz medical implant communication service (MICS) frequency band. The oscillator was designed in IBM CMOS8RF 0.13 mum CMOS technology and simulated using Cadence IC5.141. The current reuse structure draws half the bias current as a conventional quadrature voltage controlled oscillator while exhibiting performance comparable to or exceeding that of previously published designs. Simulation results show that the oscillator phase noise is -127 dBc/Hz and consumes 1 mW of power from a 1 V supply. When the supply voltage is scaled to 0.65 V and biased for the same current consumption, the power consumption is reduced to 650 muW with phase noise of -111 dBc/Hz, which is almost 50% less power consumption when compared to oscillators in the same frequency band. The tuning range of the oscillator is 401.25 MHz to 407.5 MHz, enough to cover the MICS frequency band.