A 0.48 mW fully integrated MICS band VCO in SiGe BiCMOS technology for medical implant communication

This paper presents the design of a low power VCO, that is a part of a fully integrated, directly modulated, VCO-only transmitter in MICS band (402–405 MHz). The differential LC-tank VCO is designed for a MSK transmitter supporting up to 200 kbps data rate for the application in a glucose sensor implant. The chip is fabricated in the CMOS section of IHPs 0.13 μm SiGe BiCMOS process and has an active area of 0.86 mm2. The measured VCO has shown −110 dBc/Hz phase noise at 200 kHz offset from the carrier and a tuning range of 22.6 MHz (5.6 %), while consuming 0.55 mA from a 0.87 V supply (0.48 mW). The phase noise performance, size and power consumption of the measured VCO satisfy the requirements of implantable electronics. This VCO is therefore an important block in building a more complex, multi-channel MICS band transmitter.