Ring Oscillator Based Voltage Controlled Oscillator Design for IoT Based Wireless Patient Monitoring Station in 50 nm CMOS Process

Healthcare professionals are quite concerned with constantly monitoring their patients. An Internet of Things (IoT) based wireless health monitoring station can be a viable option to reduce human labor. The design study of a single-ended ring oscillator-based voltage-controlled oscillator (RO-VCO) optimized for implementation in an IoT-based wireless health monitoring system is presented in this paper. The schematic was created using a 50 nm CMOS process. By varying the control voltage from 0.9 V to 1.5 V the voltage-controlled oscillator can operate at 1.67 to 3.13 GHz. A supply voltage of 1 V was used to achieve the oscillation frequency of 2.4 GHz. Such a VCO will be an essential module for the proposed IoT-based patient monitoring station and other ISM band applications.