A D-Band LNA Exploiting Ultra-Wideband Sixth-Order Matching Networks in SiGe BiCMOS

Emerging applications in the Sub-THz bands need ultra-wideband amplifiers, able to cover the wide available spectrum portions with a single component. Techniques such as distributed amplifiers or stagger-tuning are commonly adopted, at the cost of power efficiency, linearity and noise figure degradation. This paper proposes a design flow for ultra-wideband matching networks with a sixth-order frequency response. The networks fit well into the layout, absorbing parasitics and embedding the interconnections for signal propagation, biasing and supply of the active stages. The networks are exploited in the design of a 3-stage D-band low-noise amplifier in a SiGe BiCMOS technology. Experiments demonstrate 105- to- $175 \mathrm{GHz}-3 \mathrm{~dB}$ bandwidth with 23 dB gain. The fractional bandwidth, in excess of 50%, is among the highest reported in similar frequency bands. Simultaneously, a very low noise figure, ranging from 5 dB to 6.5 dB, confirms the validity of the proposed approach to enhance the performance of mm-Wave wideband amplifiers.