An improved 433MHz low power transmitter for batteryless tire pressure monitor system

This paper presents the design and implementation of a 433MHz low-power transmitter (LPT) using OOK modulation for Tire Pressure Monitor System (TPMS). The proposed direct modulation transmitter radiates -10dBm with 10mA power dissipation, which fulfill the requirement of the application. The transmitter has a direct PLL modulation architecture using an integral synthesizer and a power efficient power amplifier. The transmitter is implemented in the UMC 0.18um RFCMOS process, and the chip area is 1.1mm×0.877mm. Finally, the chip is tested with a Chip-on-Board (COB) package.