PROJECT TITLE :

CMOS RF Transmitter Using Pulsewidth Modulation for Wireless Smart Sensors

ABSTRACT:

This paper presents the radio frequency (RF) transmitter using pulsewidth modulation (PWM) method. The proposed transmitter can perform with lower power consumption compared to different RF transmitters using a conventional ring oscillator as a result of the proposed voltage-controlled oscillator (VCO) is operated by ON-/OFF-time of the PWM signal. Moreover, the proposed VCO with a metal-oxide semiconductor switch can cut back the ability consumption significantly due to the reduction of idle current loss. The ability dissipation of the transmitter is measured as zero.75 mW at a carrier of 315 MHz. The transmission of the modulated signal is performed by the on-chip antenna with bond-wire inductor. The on-chip antenna has gain of $-rm 34.33~rm dBi$. The radiated power is measured as $-rm 32.3~rm dBm$ at a distance of 10 cm between the receiver and the transmitter.