This article proposes a dual-band complementary metal–oxide–semiconductor (CMOS) radio frequency (RF) front end employing a hybrid transformer-based electrical-balance duplexer (EBD) and $N$ -path filter embedded low-noise amplifier (LNA) for both in-band full duplexing (IBFD) and frequency-division duplexing (FDD) radios. To securely obtain sufficient self-interference cancellation (SIC) or transmitter (TX) leakage rejection in IBFD and FDD modes of the EBD at both low-band (LB) (0.7–1 GHz) and mid-band (MB) (1.8–2.2 GHz) frequency ranges, a band-switchable hybrid transformer is designed with a finely adjustable balance network to control the antenna impedance variations. In addition, the four-phase $N$ -path LNA is utilized to further offer TX leakage rejection in the FDD operation. This RF front-end is fabricated using a 65-nm CMOS technology and is mainly characterized by long-term evolution frequency bands. The demonstrated design achieves SIC and TX leakage rejection greater than 55 dB for IBFD and FDD modes of all measured frequency bands, which has a maximum power handling capability of +25 dBm. Furthermore, the design attains voltage gains greater than 8.7 dB for LB and 3.7 dB for MB, noise figures of 10.4 dB for LB and 12.1 dB for MB, out-of-band (OB) P1dBs greater than +21.4 dBm for LB and +21.5 dBm for MB, and OB IIP3s greater than +39.7 dBm for LB and +43.1 dBm for MB. It draws a bias current of 23.8 mA from the LNA and output buffer with a nominal supply of 1.2 V and has an active area of approximately 2 mm ² .

中文翻译：

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采用电平衡双工器的双频 CMOS 射频前端和 N-IBFD 和 FDD 无线电的路径 LNA

本文提出了一种双频互补金属氧化物半导体 (CMOS) 射频 (RF) 前端，该前端采用基于混合变压器的电平衡双工器 (EBD) 和 $N$ -path 滤波器嵌入式低噪声放大器 (LNA)，适用于带内全双工 (IBFD) 和频分双工 (FDD) 无线电。为了在低频段 (LB) (0.7–1 GHz) 和中频段 (MB) (1.8–) 的 EBD 的 IBFD 和 FDD 模式下安全地获得足够的自干扰消除 (SIC) 或发射机 (TX) 泄漏抑制2.2 GHz) 频率范围内，设计了一个带可微调平衡网络的频段可切换混合变压器，以控制天线阻抗变化。此外，四相 $N$ -path LNA 用于在 FDD 操作中进一步提供 TX 泄漏抑制。该射频前端采用 65 纳米 CMOS 技术制造，主要特点是长期演进频段。所演示的设计在所有测量频段的 IBFD 和 FDD 模式下实现了大于 55 dB 的 SIC 和 TX 泄漏抑制，其最大功率处理能力为 +25 dBm。此外，该设计使 LB 的电压增益大于 8.7 dB，MB 的电压增益大于 3.7 dB，LB 的噪声系数为 10.4 dB，MB 的噪声系数为 12.1 dB，LB 和 + 的带外 (OB) P1dB 大于 +21.4 dBm MB 为 21.5 dBm，LB 大于 +39.7 dBm，MB 大于 +43.1 dBm。它从 LNA 和输出缓冲器吸取 23.8 mA 的偏置电流，标称电源为 1.2 V，有效面积约为 2 mm ² .