This letter describes the design, analysis, and testing of a 28-GHz single-input differential-output (SIDO) low-noise amplifier (LNA) with a noise figure of 2.5 dB, compact size (0.25 mm²), and high gain (22.3 dB). The proposed LNA was fabricated using the Taiwan Semiconductor Manufacturing Company (TSMC) 65-nm CMOS process. This amplifier contains a two-stage common-source (CS) buffer amplifier for a low-noise design and combines CS and common-gate transistors for converting single-ended signal into differential signal. A novel method of common-mode rejection ratio optimization is used to determine the optimal phase compensation transmission line and transistor size to reduce gain and phase imbalances simultaneously. The gain and phase imbalances were 0.042 dB and 2.6° at 28 GHz, respectively. Compared with published LNAs, this SIDO LNA achieved the high figure of merits (FoMs) of 7.17 and 2.27, respectively. Therefore, this LNA can be used for 5G NR band of n257 (26.5-29.5 GHz), n258 (24.25-27.5 GHz), and n261 (27.5-28.35 GHz).
- 5G mobile communication
- Integrated circuits
- Noise measurement
- Phased arrays
- common-mode rejection ratio (CMRR)
- low-noise amplifier (LNA)
- monolithic microwave integrated circuit (MMIC)
- single-input differential-output (SIDO).