A Fully Integrated 300-MHz Channel Bandwidth 256 QAM Transceiver With Self-Interference Suppression in Closely Spaced Channels at 6.5-GHz Band

We present a fully-integrated 256 QAM single-chip transceiver (TRX) with 300-MHz channel bandwidth at the 6.5-GHz band. A novel architecture for self-interference suppression (SIS) is proposed. A noise-canceling low-noise amplifier with the embedded programmable source degeneration network based on the bond wires, manifesting the notch filtering characteristics of the self-interference signal, has been utilized to facilitate the SIS, and LC-tuned tanks further improve the interference filtering in a receiver (RX) and considerable adjacent channel leakage power ratio in a transmitter (TX). The SAW-less /duplexer-less TRX allows TDD/FDD co-operation in closely spaced channels. The RX achieves a noise figure (NF) as low as 3 dB with +17.5-dBm out-of-band IIP3. The EVM is 2.02% and 2.72% for the RX and TX, respectively, in 160-MHz bandwidth OFDM 256 QAM. In the SIS mode, the blocker P1dB is -8 dBm, and the NF of the RX degrades only 2.1 dB (from 3.0 to 5.1 dB), withstanding 0-dBm interference at 150-MHz offset. The TRX exhibits a slight EVM degradation (from 2.02% to 2.98%) when receiving a -40-dBm 160-MHz bandwidth 256 QAM desired signal, in the presence of a -15-dBm 80-MHz bandwidth self-interference signal at 300-MHz offset. The TRX has been implemented in 0.13-$\mu \text{m}$ CMOS with superior overall performances.