A CMOS Transmitter Analog Baseband for 5G Mobile Communication

• Main Authors: Ming-Yu Yen, Hsiao-Chin Chen, Yu-Lun Wei, Chi-Yin Chung
• Format: Article
• Language: English
• Published: MDPI AG 2019-11-01
• Series: Electronics
• Subjects: 5g mobile communication; analog baseband; low-pass filter (lpf), programmable gain amplifier (pga), super source follower; transmitter
• Online Access: https://www.mdpi.com/2079-9292/8/11/1319

CMOS analog baseband circuits including a low-pass filter (LPF) and a programmable gain amplifier (PGA) are designed and implemented for the fifth-generation (5G) mobile communication. The super source follower topology is adopted to achieve a wideband LPF with good linearity, while the constant current density gain control technique is used to implement gain cells of the PGA. The circuits are integrated as an analog baseband for a 5G transmitter (TX) and fabricated using TSMC 90-nm CMOS technology. The analog baseband exhibits the bandwidth from 1.03 to 1.05 GHz when the voltage gain is varied from −18.9 dB to 3.8 dB in 1-dB steps. The gain step errors are within −0.7 dB to 0.9 dB. In the highest gain mode, the analog baseband achieves the IP_1dB of −10 dBv and the IIP3 of −0.2 dBv. Over the band of interest, the NF of the analog baseband is 24.4−40.0 dB.