Kim Nam-Seog
Department of Information and Communication Engineering, School of Electrical and Computer Engineering, Chungbuk National University, Cheongju-Si 28644, Republic of Korea.
Sensors (Basel). 2024 Mar 1;24(5):1616. doi: 10.3390/s24051616.
Short-range Internet of Things (IoT) sensor nodes operating at 2.4 GHz must provide ubiquitous wireless sensor networks (WSNs) with energy-efficient, wide-range output power (POUT). They must also be fully integrated on a single chip for wireless body area networks (WBANs) and wireless personal area networks (WPANs) using low-power Bluetooth (BLE) and Zigbee standards. The proposed fully integrated transmitter (TX) utilizes a digitally controllable current-mode class-D (CMCD) power amplifier (PA) with a second harmonic distortion (HD2) suppression to reduce VCO pulling in an integrated system while meeting harmonic limit regulations. The CMCD PA is divided into 7-bit slices that can be reconfigured between differential and single-ended topologies. Duty cycle distortion compensation is performed for HD2 suppression, and an HD2 rejection filter and a modified C-L-C low-pass filter (LPF) reduce HD2 further. Implemented in a 28 nm CMOS process, the TX achieves a wide P range of from 12.1 to -31 dBm and provides a maximum efficiency of 39.8% while consuming 41.1 mW at 12.1 dBm P. The calibrated HD2 level is -82.2 dBc at 9.93 dBm P, resulting in a transmitter figure of merit (TX_FoM) of -97.52 dB. Higher-order harmonic levels remain below -41.2 dBm even at 12.1 dBm P, meeting regulatory requirements.
工作在2.4GHz频段的短距离物联网（IoT）传感器节点必须为无处不在的无线传感器网络（WSN）提供节能、宽范围输出功率（POUT）。它们还必须完全集成在单个芯片上，用于使用低功耗蓝牙（BLE）和Zigbee标准的无线体域网（WBAN）和无线个人区域网（WPAN）。所提出的全集成发射机（TX）采用了具有二次谐波失真（HD2）抑制功能的数字可控电流模式D类（CMCD）功率放大器（PA），以减少集成系统中的压控振荡器（VCO）牵引，同时满足谐波限制规定。CMCD PA被划分为7位切片，可以在差分和单端拓扑之间重新配置。为抑制HD2进行占空比失真补偿，并且一个HD2抑制滤波器和一个改进的C-L-C低通滤波器（LPF）进一步降低HD2。该TX采用28nm CMOS工艺实现，实现了12.1至-31dBm的宽功率范围，在12.1dBm输出功率（POUT）下消耗41.1mW时提供了39.8%的最大效率。在9.93dBm输出功率（POUT）下校准的HD2电平为-82.2dBc，从而得到-97.52dB的发射机品质因数（TX_FoM）。即使在12.1dBm输出功率（POUT）下，高阶谐波电平仍保持在-41.2dBm以下，满足监管要求。
