The design and measured results of a 120 GHz / 140 GHz dual-channel amplitude shift keying (ASK) receiver are presented in this paper. Because a signal with very wide frequency width of over 10 GHz is difficult to process in a single-channel transceiver, a dual-channel configuration with channel selection is adopted in the proposed receiver. The proposed receiver is fabricated using standard 65 nm CMOS technology. The measured data rate of 3.0 Gbps, minimum sensitivity of −25.6 dBm, communication distance of 0.3 m and correct channel selection property are achieved in the 120-GHz receiver. These results indicate the possibility of the CMOS multiband receiver operating at over 100 GHz for high-speed wireless communication systems.