Constant Loss Contours of Matching Networks for Millimeter-Wave LNA Design

This letter presents a new tool of constant loss contours for matching network loss evaluation. With a certain source impedance, the contours illustrate the matching loss while an arbitrary load impedance is matched to the source impedance. The contours are also applied to millimeter-wave circuit design to help designers consider the circuit topologies, transistor sizes, and layout effects. A millimeter-wave CMOS low-noise amplifier has been optimized by using the constant loss contours. The measured results show a low noise figure of 4.85 dB and a gain of 21.0 dB at 79.5 GHz while only consuming 8 mW from a 1.0 V supply.