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.