Stability Analysis of Parasitic Coupling Between on-Chip Antenna and mm-Wave Front-End

Abstract

This paper investigates spurious oscillations caused by coupling between an on-chip antenna and a mm-wave front-end through a closed-loop stability analysis methodology. The methodology is applied to a 120 GHz receiver with integrated dipole antenna. By injecting a small-signal current source the circuit is linearized around its dc steady-state to create a closed-loop transfer function. For this function start-up conditions for oscillation are verified, as well as the detection of unstable right-halve plane poles through a fitting algorithm. This method is preferred over traditional methods, such µ or k-factor analyses, as they can only be defined for two-port networks.