Multi-band inductor-less VCO for IoT applications

This brief presents a reconfigurable inductor-less voltage controlled oscillator (VCO) with low-power and low-cost performances making it suitable for IoT applications and applicable to the multi-standards. It uses an active inductor based on n-bits controlled CMOS inverters for coarse frequency tuning and diode varactor for fine frequency tuning. The example of a 3 bit digitally controlled oscillator has been implemented in a 0.13μm CMOS process. It can cover a frequency tuning of 1.28–2.6 GHz and thus can support the different standards of 2G, 3G, 4G and future 5G wireless systems. The fabricated LC-VCO occupies a small active area of only (54 × 59)μm2. The phase noise is −87 dBc/Hz @ 1MHz with a power consumption less than 4mW at a supply of 1.1V.