Optical beam-forming networks (OBFNs) based on optical true-time delay lines (OTTDLs) are well known as the promising candidate for solving the bandwidth limitation of traditional electronic phased array antennas (PAAs) due to beam squinting. Here we report, to the best of our knowledge, the first monolithic $1 \times 8$ microwave photonic beamformer, based on switchable OTTDLs on the silicon-on-insulator platform. The chip consists of a modulator, an eight-channel OBFN, and eight photodetectors, thus including hundreds of active and passive components in total. It has a wide operating bandwidth from 8 to 18 GHz, which is almost two orders larger than that of electronic PAAs. The beam can be steered to 31 distinguishable angles in the range from ${-}{75.51}^\circ$ to 75.64°, based on the beam pattern calculation with the measured radiofrequency response. The response time for beam steering is 56 µs. These results represent a significant step toward the realization of integrated microwave photonic beamformers that can satisfy compact-size and low-power consumption requirements for the future radar and wireless communication systems.

中文翻译：

---

硅集成微波光子束形成器

基于光学实时延迟线（OTTDL）的光束形成网络（OBFN）是众所周知的解决波束斜视导致的传统电子相控阵天线（PAA）带宽限制的有前途的候选者。在此，我们以我们所知，报告了第一款基于绝缘体上硅平台上的可切换OTTDL的单片1美元乘8美元的微波光子波束形成器。该芯片由一个调制器，一个八通道OBFN和八个光电检测器组成，因此总共包括数百个有源和无源组件。它具有8至18 GHz的宽工作带宽，几乎是电子PAA的两个数量级。光束可以转向31个可识别的角度，范围从$ {-} {75.51} ^ \ circ $到75.64°，基于光束图计算和测得的射频响应。光束转向的响应时间为56 µs。这些结果代表了朝着实现集成微波光子波束形成器迈出的重要一步，该波束形成器可以满足未来雷达和无线通信系统的紧凑尺寸和低功耗要求。