A CMOS UWB pulse beamforming transmitter with Vivaldi array antenna for vital signals monitoring applications

This paper presents a new beamforming transmitter, Ultra Wide Band (UWB) pulse generator for contactless radar monitoring applications of vital signals. The system consists of a programmable delay circuit (PDC or τ), UWB pulse generator circuit and an array of Vivaldi planar antennas. Also, a new CMOS PDC controller is developed in order to provide pulse beamforming. The circuit was designed using 0.18μm CMOS process and the planar antenna array was designed with copper and FR-4 substrate. Spice circuit simulations show the generation of pulses with 136mVpp amplitudes and 350ps width. The generated pulse spectrum complies with the Federal Communications Commission (FCC) spectrum mask in the 6-10GHz range. The dynamic energy consumption is around 0.4pJ per pulse using 2V power supply at pulse repetition rate (PRR) of 100MHz. Electromagnetic simulations using CST MW 2010 shows the Main Lobe with an average magnitude of 12dBi, 30° × 32° angular width, and a beam steering between -15° and +25° for θ, and between -20° and +20° for the φ angles. This system can be applied to human monitoring in hospitals, ports and airports, industrial plants - like refineries and oil platforms - and military units as well.