305-325 GHz Non-Reciprocal Isolator Based on Peak-Control Gain-boosting Magnetless Non-reciprocal Metamaterials

Terahertz (THz) non-reciprocal components such as circulators, isolators, filters, and gyrators are anticipated to play vital roles in THz system. However, to the best of our knowledge, silicon-based THz non-reciprocal components have not been reported. This paper presents the first silicon-based THz magnetic-free non-reciprocal isolator in SiGe BiCMOS process
$(f_{T}/fmax=\mathrm{300}/\mathrm{450}\ \text{GHz})$
, covering 305–325 GHz. Peak-control gain-boosting technique is utilized to push the operating frequency of the magnetless non-reciprocal metamaterials (MNMs) to THz spectrum. By cascading three MNMs operating at different frequencies, a wideband non-reciprocal isolator is achieved. It exhibits 3.6 dB loss (with pad) and 15.3 dB isolation while consuming 3.52 mW (1.17 mW/unit) from 0.88-V supply.