A novel gain‐boosting structure with Z‐embedding and parallel pre‐embedding network for amplifiers at near‐fmax frequencies

Abstract

SummaryIn this paper, a novel gain‐boosting structure with Z‐embedding and parallel pre‐embedding network (Z/pre‐Y‐embedding) is proposed to improve the power gain of amplifier at near‐fmax frequencies. Gain‐plane approach has been adopted to study the proposed Z/pre‐Y‐embedding technique. Analytical formula has been derived to calculate the required embedding elements to achieve the upper limit of the maximum available gain. The proposed technique exhibits an attractive advantage that it can absorb the external parasitics of the transistor into the Z/pre‐Y‐embedding network. Based on the proposed gain‐boosting structure, a three‐stage amplifier is designed in a 130 nm SiGe process to verify the power gain improvement. It exhibits a power gain of 21.1 dB at 230 GHz, which is 11.1 dB higher than the three‐stage amplifier without any gain‐boosting technique.