Future devices for the Internet of Things will require communication systems that can deliver higher data rates at low power. Backscatter radio—in which wireless communication is achieved via reflection rather than radiation—is a low-complexity approach that requires a minimal number of active elements. However, it is typically limited to data rates of hundreds of megabits per second because of the low frequency bands used and the modulation techniques involved. Here we report a millimetre-wave modulator and antenna array for backscatter communications at gigabit data rates. This radiofrequency front-end consists of a microstrip patch antenna array and a single pseudomorphic high-electron-mobility transistor that supports a range of modulation formats including binary phase shift keying, quadrature phase shift keying and quadrature amplitude modulation. The circuit is additively manufactured with inkjet printing using silver nanoparticle inks on a flexible liquid-crystal polymer substrate. A millimetre-wave transceiver is also designed to capture and downconvert the backscattered signals and route them for digital signal processing. With the system, we demonstrate a bit rate of two gigabits per second of backscatter transmission at millimetre-wave frequencies of 24–28 GHz, and with a front-end energy consumption of 0.17 pJ per bit.

未来的物联网设备将需要能够以低功耗提供更高数据速率的通信系统。反向散射无线电——通过反射而不是辐射实现无线通信——是一种低复杂度的方法，需要最少数量的有源元件。然而，由于使用的低频段和所涉及的调制技术，它通常限于每秒数百兆比特的数据速率。在这里，我们报告了一种毫米波调制器和天线阵列，用于千兆数据速率的反向散射通信。该射频前端由微带贴片天线阵列和单个伪高电子迁移率晶体管组成，支持多种调制格式，包括二进制相移键控、正交相移键控和正交幅度调制。该电路是通过喷墨打印在柔性液晶聚合物基板上使用银纳米粒子墨水增材制造的。毫米波收发器还设计用于捕获和下变频反向散射信号，并将它们路由以进行数字信号处理。借助该系统，我们展示了在 24-28 GHz 毫米波频率下，反向散射传输的比特率为每秒 2 Gb，前端能耗为每比特 0.17 pJ。