Scalable Miniature THz Radar for Industrial Applications

在过去的几年里，半导体技术取得了巨大的进步，硅基技术的阈值频率已经超过300 GHz，III-V族半导体技术的阈值频率已经达到1 THz。因此，电子电路的集成水平在100 GHz以上的频率上达到了新的高度。在如此高的频率下工作的好处是双重的。一方面，大的带宽是由于宽松的频率规定，另一方面，小的波长，使天线集成在芯片上或芯片封装。因此，可以实现具有前所未有的分辨率的超小型雷达传感器。然而，瓶颈在于开发100 GHz以上的传感器所需的高度复杂的封装和互连技术。在SATIRE转移项目中，DFG项目Real100G.RF的两种封装变体都将与Fraunhofer IAF的电子电路集成到一个可扩展的微型雷达前端中。此外，雷达前端的工业应用将与VEGA公司合作进行评估。为了实现毫米范围内的分辨率，电子电路的工作带宽应至少为50 GHz。此外，发射机应该是可切换的，以实现TDM-MIMO操作（TDM：时分复用，MIMO：多输入多输出）。天线设计将被优化，使得GaAs MMIC可以直接安装在透镜上，其介电常数位于GaAs附近。为此，将测试由介电常数与GaAs相似的陶瓷和塑料材料制成的透镜。这些镜片将与3D打印和注塑成型工艺兼容。完整的模块将与透镜本身一样大，即最大尺寸为10 mm。建议的架构包括乘法器，外部本地振荡器（LO）和可切换的发射机，使多个雷达前端在单个印刷电路板上同时工作，从而实现MIMO雷达。此外，模块中的频率倍增和封装的概念导致用于工业应用的具有成本效益的300 GHz雷达前端，其可以集成在标准印刷电路板技术中。在传感器系统的新频率范围的开发中预见了巨大的商业潜力。其目的是开发一个多方面的雷达前端，可以根据不同系统的要求进行缩放。此外，雷达前端主要针对工业应用，因为它旨在服务于具有低到中等数量系统的大量应用。因此，唯一可能的成本效益的解决方案是开发一个多方面的标准芯片，包括封装。

The past few years have witnessed a tremendous progress in the semiconductor technology, which has increased the threshold frequency beyond 300 GHz for silicon-based technologies and up to 1 THz for III-V semiconductor technologies. As a result, the level of integration in electronic circuits is achieving new heights at frequencies above 100 GHz. The benefits of operating at such high frequencies are twofold. On one hand, a large bandwidth is available by virtue of relaxed frequency regulations and on the other hand, a small wavelength enables integration of antennas either on the chip or in the chip-package. Therefore, ultra-compact radar sensors with an unprecedented resolution can be realized. However, the bottleneck lies in the highly-complex packaging and interconnection technology required for developing such sensors above 100 GHz. Since long, this has been a limiting factor in realizing cost-effective fully-integrated modules.In transfer project SATIRE, both the package variants from the DFG project Real100G.RF will be integrated with Fraunhofer IAF‘s electronic circuits into a scalable, miniature-sized radar frontend. Additionally, the industrial application of the radar frontend will be evaluated in cooperation with the company VEGA. In order to achieve a resolution in the millimeter-range, the operating bandwidth of the electronic circuit should be at least 50 GHz. Additionally, the transmitter should be switchable for enabling TDM-MIMO operation (TDM: Time Division Multiplex, MIMO: Multiple Input Multiple Output). The antenna design will be optimized such that the GaAs MMIC can be directly mounted on a lens, whose dielectric constant lies in the vicinity of GaAs. For this purpose, lenses made of ceramic and plastic materials with dielectric constant similar to GaAs, will be tested. These lenses will be compatible with 3D printing and injection molding process. The complete module will be as large as the lens itself, i.e. a maximum size of 10 mm. The proposed architecture consisting of multipliers, an external local oscillator (LO) and a switchable transmitter, enables simultaneous operation of multiple radar frontends on a single printed circuit board; thus realizing a MIMO radar. Further, the concepts of frequency multiplication and encapsulation in a module lead to a cost effective 300 GHz radar frontend for industrial applications, which can be integrated in standard printed circuit board technology. A great commercial potential is foreseen in the exploitation of the new frequency range for sensor systems. The aim is to develop a multi-faceted radar frontend, which can be scaled according to the requirements of different systems. Further, the radar frontend is mainly targeted for industrial applications, since it is intended to serve a large number of applications with low to medium number of systems. Consequently, the only possible cost-effective solution is to develop a multi-faceted standard chip including package.