Active THz Transceiver Components

与在纯光学波长或RF/微波频率下工作的无线电相比，太赫兹频率下极高的绝对带宽和高相对带宽的组合，加上在所谓的“太赫兹间隙”中工作的技术的严重性能限制，对依赖高信号完整性的现代数字传输方案提出了独特的挑战。由于在太赫兹频率下还没有直接的DSP，所以信号需要频移到太赫兹范围内或从太赫兹范围内移出。这种频移是由收发器来完成的，收发器可以基于全电子、全光子或混合电子-光子技术来实现。后一种方法是目前最有前途的方法，因为它可以结合两个领域的独特优势，即基于电子的太赫兹收发器的低接收器噪声，高发射功率和高功能集成密度，以及基于光子学的太赫兹信号产生的高光谱纯度和高质量相位和频率控制。Meteracom的B2项目旨在发展基于电子和光子技术的太赫兹收发器设计的理论和实验理解，以及优化其特定应用特性的电路设计和仿真方法，以提高其数据速率能力、调制格式通用性和系统增益。该项目还将为在其他项目框架内研究的太赫兹计量概念的实验验证提供技术平台。将研究在220至325 GHz WR3频率范围内工作的电子太赫兹收发器电路，特别关注在太赫兹通信、雷达和计量应用中遇到的超宽带（bbb60 GHz）信道带宽。在基于理论分析和系统级CAD仿真的面向应用的自顶向下设计方法中，将研究通信信号的矢量信号退化对外差、正交电子太赫兹发射接收前端损伤的敏感性，并进行实验评估，最后在专用收发电路设计中最小化。作为有源太赫兹收发器的补充，将研究在锁模激光器的帮助下产生高度稳定和光谱纯净的基于光子的信号，作为可调谐太赫兹信号源和电子收发器的稳定本地振荡器。该项目的实验验证将包括单个电子和光子收发器组件的时域和频域特性，以及使用背靠背配置的组合光子-电子收发器的完整数据传输实验，以及现有的具有空中接口的太赫兹收发器。

Compared to radios operating at purely optical wavelengths or RF/microwave frequencies, the combination of extremely high absolute bandwidths and high relative bandwidths in the THz frequency regime, paired with the severe performance limitations of technologies operating in the so-called "THz-gap", imposes unique challenges on modern digital transmission schemes relying on high signal integrity. Since no direct DSP is yet possible at THz frequencies, signals need to be frequency-shifted into and from the THz range. This frequency-shifting is performed by the transceiver, which can be implemented based either on fully electronic, fully photonic or mixed electronic-photonic technologies. The latter approach is today the most promising way forward since it allows to combine the unique advantages of both domains, namely the low receiver noise, high transmit power and high functional integration density of electronics-based THz transceivers, with the high spectral purity and high quality phase and frequency control of photonics-based THz signal generation.Project B2 of Meteracom aims at developing a theoretical and experimental understanding of the design of THz transceivers based on electronic and photonic technologies, as well as circuit design and simulation methods of optimizing their application-specific characteristics, in view of pushing their data rate capability, modulation format versatility and system gain. The project will also provide a technology platform for the experimental validation of the Terahertz metrology concepts investigated in the frame of the other projects.Electronic THz transceiver circuits operating within the WR3 frequency range from 220 to 325 GHz will be investigated, with a particular focus on ultra-wideband (> 60 GHz) channel bandwidths, as encountered in THz communication, radar and metrology applications. In an application-oriented top-down design approach based on theoretical analysis and system-level CAD simulations, the sensitivity of the vectorial signal degradation of communication signals on the impairments of heterodyne, quadrature electronic THz transmit receive frontends will be studied, experimentally evaluated, and finally minimized in dedicated transceiver circuit design.Complementing the active THz transceivers, highly stable and spectrally pure photonics-based signal generation with the help of mode-locked lasers will be investigated, serving, both, as a tunable THz signal source and as a stable local oscillator to the electronic transceivers.Experimental validation in this project will comprise the time and frequency domain characterisation of the individual electronic and photonic transceiver components, as well as complete data transmission experiments using combined photonic-electronic transceivers in a back-to-back configuration, as well as existing THz transceivers with air interface from prior art.