A SiGe BiCMOS ultra wide band RFIC transmitter design for wireless sensor networks

An ultra wide band (UWB) transmitter has been designed for integration with sensor readout and data conversion circuitry for wireless sensor network applications. The transmitter operates over three 500 MHz bands at center frequencies of 4.6/6.4/8.0 GHz, and generates pulses with BPSK modulation. While hopping between the different bands, the transmitter is capable of settling and retransmitting in less than 0.7 μs using an internal fast lock phase-locked loop (PLL). An 8-bit successive approximation ADC is also implemented to interface with the sensor readout circuitry. The 8-bit parallel output from the ADC is then converted to serial signal at the transmitter data input port. The design is currently being fabricated through Freescale Semiconductor´s (formerly Motorola SPS) HIP6WRF BiCMOS process. A prototype switched tank VCO with 2-bands (4.4/5.4 GHz) was fabricated in the same technology with reasonable tuning ability.