Ahn Hyunjin, Oh Kyutaek, Choi Se-Eun, Son Dong-Hee, Nam Ilku, Lim Kyoohyun, Lee Ockgoo
Qualcomm Inc., San Diego, CA 92121, USA.
Department of Electrical Engineering, Pusan National University, Busan 46241, Republic of Korea.
Nanomaterials (Basel). 2024 Jan 25;14(3):262. doi: 10.3390/nano14030262.
The narrowband Internet-of-Things (NB-IoT) has been developed to provide low-power, wide-area IoT applications. The efficiency of a power amplifier (PA) in a transmitter is crucial for a longer battery lifetime, satisfying the requirements for output power and linearity. In addition, the design of an internal complementary metal-oxide semiconductor (CMOS) PA is typically required when considering commercial applications to include the operation of an optional external PA. This paper presents a dual-mode CMOS PA with an external PA driver for NB-IoT applications. The proposed PA supports an external PA mode without degrading the performances of output power, linearity, and stability. In the operation of an external PA mode, the PA provides a sufficient gain to drive an external PA. A parallel-combined transistor method is adopted for a dual-mode operation and a third-order intermodulation distortion (IMD3) cancellation. The proposed CMOS PA with an external PA driver was implemented using 40 nm-CMOS technology. The PA achieves a gain of 20.4 dB, a saturated output power of 28.8 dBm, and a power-added efficiency (PAE) of 57.8% in high-power (HP) mode at 920 MHz. With an NB-IoT signal (200 kHz π/4-differential quadrature phase shift keying (DQPSK)), the proposed PA achieves 24.2 dBm output power (Pout) with a 31.0% PAE, while satisfying -45 dBc adjacent channel leakage ratio (ACLR). More than 80% of the current consumption at 12 dBm Pout could be saved compared to that in HP mode when the proposed PA operates in low-power (LP) mode. The implemented dual-mode CMOS PA provides high linear output power with high efficiency, while supporting an external PA mode. The proposed PA is a good candidate for NB-IoT applications.
窄带物联网（NB-IoT）已得到发展，以提供低功耗、广域物联网应用。发射机中功率放大器（PA）的效率对于延长电池寿命、满足输出功率和线性度要求至关重要。此外，在考虑商业应用时，通常需要设计内部互补金属氧化物半导体（CMOS）功率放大器，以包括可选外部功率放大器的运行。本文提出了一种用于NB-IoT应用的具有外部PA驱动器的双模CMOS功率放大器。所提出的功率放大器支持外部PA模式，而不会降低输出功率、线性度和稳定性。在外部PA模式运行时，该功率放大器提供足够的增益来驱动外部功率放大器。采用并联组合晶体管方法实现双模运行和三阶互调失真（IMD3）消除。所提出的具有外部PA驱动器的CMOS功率放大器采用40nm-CMOS技术实现。该功率放大器在920MHz的高功率（HP）模式下实现了20.4dB的增益、28.8dBm的饱和输出功率和57.8%的功率附加效率（PAE）。对于NB-IoT信号（200kHz π/4差分正交相移键控（DQPSK）），所提出的功率放大器实现了24.2dBm的输出功率（Pout）和31.0%的PAE，同时满足-45dBc的邻道泄漏比（ACLR）。当所提出的功率放大器在低功率（LP）模式下运行时，与HP模式相比，在12dBm Pout时可节省超过80%的电流消耗。所实现的双模CMOS功率放大器在支持外部PA模式的同时，提供了高效率的高线性输出功率。所提出的功率放大器是NB-IoT应用的良好候选方案。
