A 1024-QAM capable WLAN receiver with −56.3 dB image rejection ratio using self-calibration technique

This paper presents a 1024-QAM OFDM signal capable WLAN receiver in 65 nm CMOS technology. Thermal noise-based IQ frequency-independent mismatch correction and IQ frequency-dependent mismatch correction with baseband loopback are proposed for the self-calibration in the receiver. By using proposed calibration method, neither received external signal nor RF loopback are necessary and the residual IQ mismatch of TXBB can be removed. The measured image rejection ratio of the self-calibration is −56.3 dB. The receiver achieves the extremely low EVM of −37.1 dB even with wide channel bandwidth of 80 MHz and has the ability to receive the 1024-QAM signal. The result indicates that the receiver is extendable for the 802.11ax compliant receiver that supports a higher density modulation scheme of MIMO.