A 220 – 320 GHz High Image Rejection Sideband Separating Receiver for Space-borne Observatories

This work presents a novel terahertz THz sideband separating receiver (SSR) implemented in silicon germanium (SiGe) 0.13 μm BiCMOS technology that covers a broad frequency range of 220-320 GHz. The proposed architecture provides simultaneous observation of spectral lines with high image rejection ratio (IRR) across the entire operating frequency range. The double down conversion architecture with a first mixer operating as a sub-harmonic mixer was configurated as a sideband separating receiver leveraging the Weaver topology to provide two differential channels, one for the upper sideband (USB) and one for the lower sideband (LSB). The presented design demonstrates an IRR exceeding 20 dB across the entire frequency range of 220- 320 GHz, without the need for calibration. To the best of the author's knowledge, this is the first reported H-band simultaneous sideband separation receiver in silicon technology. The fabricated receiver measures 1.2×1 mm2 and consumes 19 mW (not including LO power consumption), showcasing its potential for application in multiple-pixel arrays for space-borne observations.

本研究提出一款新型太赫兹（terahertz，THz）边带分离接收机（sideband separating receiver，SSR），采用硅锗（SiGe）0.13 μm BiCMOS工艺实现，工作频段覆盖220~320 GHz的宽频范围。所提出的架构可在全工作频段内实现高镜像抑制比（image rejection ratio，IRR）的谱线同步观测。该设计采用二次下变频架构，第一级混频器为次谐波混频器，依托韦弗拓扑结构实现边带分离，可提供两路差分信道，分别对应上边带（upper sideband，USB）与下边带（lower sideband，LSB）。本设计在220~320 GHz的全频段内镜像抑制比均超过20 dB，且无需额外校准。据作者所知，本研究是首个在硅基工艺中报道的H波段同步边带分离接收机。该制备完成的接收机芯片尺寸为1.2×1 mm²，功耗为19 mW（不含本振（local oscillator，LO）功率消耗），展现出在星载观测多像素阵列中应用的潜力。