A 28-GHz High Linearity Up-Conversion Mixer Using Second-Harmonic Injection Technique in 28-nm CMOS Technology

• Published in: IEEE microwave and wireless components letters Vol. 31; no. 3; pp. 276 - 279
• Main Authors: Wang, Ziu-Hao, Chen, Chun-Nien, Huang, Tian-Wei, Wang, Huei
• Format: Journal Article
• Language: English
• Published: IEEE 01.03.2021
• Subjects: 28-nm CMOS technology; 5G mobile communication; Distortion; Distortion measurement; Linearity; mixer; Mixers; Power generation; third-order intermodulation; Transconductance; Transistors
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2021.3051494

A 28-GHz high linearity active up-conversion mixer using 28-nm CMOS is presented in this letter. To enhance the modulated output power level under high-order modulation with IM 3 improvement in the high IF input power region, the second-order intermodulation (IM 2 ) signal injection technique is adopted. The positive third-order intermodulation (IM 3 ) signal is generated by mixing the IM 2 signal and IF input signal with transistors in the transconductance stage biasing in triode region. Therefore, by combining these opposite IM 3 signal at the output of transconductance stage, the IM 3 distortion can be alleviated. Besides, the proposed mixer achieves an IM 3 distortion improvement in a wide IF power range. The measurement results demonstrate conversion gain (CG) of −6.4 dB and output 1-dB compression point (OP 1 dB ) of −2.2 dBm with 19 mW. The two-tone measurement results exhibit 10.2 dBm output third-order intercept point (OIP 3 ). Furthermore, with the modulation measured results using single-carrier 256-QAM signal, the proposed mixer also exhibits a distinguished output power enhancement when the linearizer turns on. To the best of the author's knowledge, this design is the first demonstration and implemented of an IM 2 signal injection technique in millimeter-wave frequency, which also improves the output power level of the high-order modulation measurement.