A novel current-reuse architecture demonstrated on a two-stage GaN-on-SiC LNA

An original implementation of the current-reuse concept is presented, specifically conceived to be applied to microwave cascaded single-ended amplifiers and, unlike most examples from the literature, not requiring that the inter-stage networks be implemented in specific topologies. To demonstrate the viability of the proposed architecture, two X-band two-stage 0.5 μm GaN-on-SiC amplifiers are designed, namely a baseline version, featured by a standard DC network, and a current-reuse version, only differing in that it adopts the presented architecture. Comparing the two designs shows that this current-reuse approach can be applied to a generic cascaded single-ended amplifier with negligible impact on chip size and RF performance. Measurements on realized prototypes are in line with what achievable in the technology at hand over the whole X-band.