A Dual-Band 2×2 802.11ax Transceiver Supporting 160MHz CBW and 1024-QAM

Along with increasingly high number of connected devices and data explosion, the emerging 802.11ax promises elevated throughput and spectral efficiency by introducing 1024-QAM modulation and OFDMA. The higher modulation scheme calls for an EVM better than -35 dB, demanding very low noise and distortion from both transmitter and receiver. On the other hand, OFDMA allows multiple users to be served simultaneously with varying bandwidth within a given 20/40/80/160MHz channel and leads to additional design constraints in RF transceivers. A minimum OFDMA group, defined as resource unit (RU), consists of 26 sub-carriers, equivalent to ~2 MHz bandwidth. The high power-density poses stringent emission requirement since the allocated transmission RU may be far away from channel center frequency. This work presents transceiver design to address critical technical challenges arising from 802.11ax. Best-in-class receiving sensitivity and EVM floor are demonstrated. The transmitters can deliver up to 22dBm mask-compliant power. The output power reaches 18dBm with -35dB EVM for 80MHz 1024QAM (HE80 MCS11) transmission. Narrowband OFDMA signals can be transmitted at full power capacity, and 160MHz channel bandwidth (CBW) can also be supported without DPD.