Regenerative, Beyond-fmax, 3D-printed Terahertz Camera Transceiver (TeraCaT)

点击翻译按钮获取中文摘要

THz signals have unique properties. In contrast to optical signals, they can penetrate many dielectric surfaces. Unlike microwave signals, they allow for very high-resolution imaging, thanks to their small wavelength. To leverage the possible benefits of THz imaging in real-world applications, compact, efficient, and coherent, high sensitivity THz cameras with multi-channel signal acquisition are required. However, their realization is limited by two fundamental shortcomings. First, at THz-frequencies, conventional heterodyne transceivers suffer from low gain, especially when operating close to or beyond fmax of the transistors. Thus, the noise, power consumption, heat dissipation, and dimensions are large. Second, existing assembly and THz interconnection technologies are mostly limited to chip-scale or split-block packages. These approaches do not scale for large multichannel apertures and are not suited for flexible system design, and are often uneconomical for the production volumes that are typical in sensor technology. Those challenges will most likely not be solved in the near future with incremental improvements based on conventional approaches. Accordingly, it is the goal of TeraCaT to establish an alternative holistic THz system design methodology. The approach utilizes an unconventional coherent transceiver architecture and an integration and manufacturing technology that is based on 3D printing and dielectric waveguides. The proposed technology framework covers all aspects from chip integration, packaging, feed network, up to the integration of the massive multichannel antenna array. In TeraCaT, compact and extremely power-efficient super-regenerative integrated receiver circuits will be investigated, which enable efficient beyond-fmax operation with high amplification gain and high sensitivity. This ambitious goal is achieved with a novel 3rd-harmonic downconversion concept, structured in 2 steps: 1) Efficient low loss fundamental mixing step of the received 0.6 THz signals to a 0.2 THz IF using a pulsed local oscillator combined with a high super-regenerative amplification utilizing positive feedback; 2) Passive down-conversion to baseband. Instead of traditional chip-packaging and interconnect techniques, the complete system will be built upon a joint technology stack. It consists of 3-dimensional structures and dielectric components, which are analyzed, simulated, designed and 3D printed together with embedded integrated circuits.To show the outstanding practicability of the innovative THz system design approach TeraCaT will set up and demonstrate a fully-functional THz imaging system and the associated tailored assembly, connection, and integration technology. TeraCaT combines the complementary and profoundly proven competencies of FAU (M. Vossiek, C. Carlowitz) in radar imaging, system design, system integration, and of TU Dresden (F. Ellinger, C. Carta) regarding high frequency integrated circuits.