JSSC 2014第7期RF & Wireless0.18 µm

A Sub-nW 2.4 GHz Transmitter for Low Data-Rate Sensing Applications Patrick P . Mercier, Member , IEEE

设计了一种超低功耗2.4 GHz发射器，平均功耗78 pW，适用于低数据率传感应用。

0.18 µm CMOS, 0.8 V, 38 pJ/bit, 5 Mbps

超低功耗2.4 GHz发射器环路天线无线能量传输OOK/FSK调制

▸创新点1：采用直接RF功率振荡器拓扑结构，通过单级架构简化设计复杂度，同时结合积极的电源门控技术，实现了仅39.7 pW的待机功耗（0.8 V供电），显著降低了系统能耗。

▸创新点2：环路天线设计兼具辐射和谐振功能，不仅作为射频信号的辐射元件，还作为振荡器的谐振元件，减少了外部元件的需求，提升了系统集成度和效率。

▸创新点3：集成无线能量接收功能，利用环路天线和二极管实现无线能量传输接收，为系统供电提供启动能量，支持能量收集操作，扩展了应用场景。

▸创新点4：支持OOK和FSK双调制模式，在2.4 GHz频段下实现5 Mbps的数据速率，功耗低至38 pJ/bit，展现了高效的数据传输性能。

Abstract

This paper presents the design of a narrowband trans- mitter and antenna system that achieves an average pow er con- sumption of 78 pW when operating at a duty-cycled data rate of 1 bps. Fabricated in a 0.18 µm CM OS process, the transmitter employs a direct-RF power oscillator topolog y where a loop an- tenna acts as a both a radiative and resonant element. The low- complexity single-stage architec ture, in combination with aggres- sive power gating techniques and sizing opt imizations, limited the standby power of the transmitt er to only 39.7 pW at 0.8 V. Sup- porting both OOK and FSK modulations at 2.4 GHz, the trans- mitter consumed as low as 38 pJ/bit at an a ctive-mode data rate of 5 Mbps. The loop antenna and integrated diodes were also used as part of a wireless power transfer receiver in order to kick-start the system power supply prior to energ y harvesting operation.