Resumo:
This paper concerns the design and implementation of a 433 MHz full-duplex radio transceiver for a sensor unit. This radio is part of a 1:N star-network topology consisting of sensor units and a central unit responsible for wireless supplying energy to the sensor units and managing the raw sensor data. Each sensor unit comprises a magnetless circulator that enables simultaneous transmission and reception. The receiver of this unit consists of an energy harvesting system and an ASK demodulator. The transmitter core of this unit is an SAW sinusoidal oscillator that performs the function of a carrier, a power amplifier, and an FSK modulator as well. The measurement results show that when a power of 18 dBm excites the input rectifier of the receiver of the sensing unit, a power of 1.2 mW is generated at the output of the power oscillator of this unit.