A fully-integrated reconfigurable transceiver for narrowband wireless communication in 180nm CMOS

A fully integrated reconfigurable transceiver (TRX) in 180nm CMOS for 750–960MHz narrowband applications is presented. The low-cost TRX consists of a low-IF receiver with 180 kHz signal bandwidth, a digital polar transmitter with 3.75 kHz signal bandwidth and a fractional-N frequency synthesizer. The receiver features a passive current mode mixer to improve the linearity and avoid the noise degradation due to the 1/f noise. The on-chip I/Q mismatch calibration is introduced to improve the image rejection ratio (IRR). The Inverse Class-D power amplifier (PA) is integrated into the transmitter to achieve high output power and efficiency, and the pre-distortion is exploited to realize the DPA linearization. Besides, the digital transmitter performs the power output by digitally controlling the DPA unit array. In order to compensate for PVT variations, the DCOC, I/Q mismatch, AFC and filter frequency tuning are all integrated in the transceiver. The RX achieves 5.1dB NF, 48dB IRR and 60dB gain dynamic range with 1dB step. The DPA provides the maximum 24.2dBm output power with 28.9% PAE. Furthermore, the TX demonstrates 4.9% EVM for 891MHz DQPSK signals at 19.09dBm output power.