AI 中文总结
该研究设计并表征了一款太赫兹单片集成电路光电导外差混频器，建立了含光电导体的电路级模型，验证了其宽带性能，为太赫兹光子混频器提供了设计方法
AI 中文摘要
我们报道了一种作为真正太赫兹单片集成电路（TMIC）实现的光电导外差混频器的设计、建模及片上表征。与以往的光电导外差演示不同，该电路采用射频集成电路指标进行表征，包括输入回波损耗、射频/中频隔离、宽带阻抗匹配及转换损耗。该混频器将微腔光电导体与宽带共面匹配网络相结合，该网络包含钛分流电阻、射频直流阻挡MIM电容及射频/中频去耦电容。开发并验证了包含光电导体及分布式CPW传输线通路的电路级模型。通过片上VNA测量，在高达500 GHz的频率下对无源电路进行了实验表征，其特性与仿真结果吻合良好。在光照下，模型预测输入反射系数在215 GHz以下低于-10 dB，在500 GHz以下优于-6.5 dB。在1-500 GHz全频段内，实测与仿真的转换损耗偏差在±1 dB以内；320 GHz以下转换损耗为22.5-25.5 dB，500 GHz以下为26-34 dB。所提出的TMIC实现了宽带工作，并为未来集成太赫兹光子混频器提供了经过验证的电路设计方法
英文摘要
We report the design, modeling, and on-wafer characterization of a photoconductive heterodyne mixer implemented as a true terahertz monolithic integrated circuit (TMIC). Unlike previous photoconductive heterodyne demonstrations, the proposed circuit is characterized using RF integrated circuit metrics including input return loss, RF/IF isolation, broadband impedance matching, and conversion loss. The mixer combines a microcavity photoconductor with a broadband coplanar matching network incorporating a Ti shunt resistor, an RF DC-blocking MIM capacitor, and an RF/IF decoupling capacitor. A circuit-level model including both the photoconductor and the distributed CPW accesses is developed and validated. The passive circuit is experimentally characterized up to 500 GHz using on-wafer VNA measurements and accurately reproduced by simulation. Under illumination, the model predicts an input reflection coefficient below -10 dB up to 215 GHz and better than -6.5 dB up to 500 GHz. Measured and simulated conversion losses agree within +/-1 dB over the entire 1-500 GHz range. Conversion loss varies from 22.5-25.5 dB below 320 GHz and 26-34 dB up to 500 GHz. The proposed TMIC demonstrates broadband operation and provides a validated circuit design methodology for future integrated THz photonic mixers.
CommentsSubmitted to IEEE Transactions on Terahertz Science and Technology. 11 pages, 11 figures
