In this paper, two optimized circular quadrature amplitude modulations (C-16QAM and C-32QAM) are proposed to mitigate phase noise in millimeter-wave receivers. A six-port direct conversion receiver in a short range wireless link test bench is used to validate the concept. Those modulation techniques are performed through the optimization of both, Euclidean distance between symbols and the gap between the concentric rings of the symbol constellation. The numerical simulations and experimental results show that the proposed constellation schemes can achieve lower bit error rate (BER) compared to the typical squares 16-QAM and 32-QAM, and other C-16QAM and C-32QAM modulations, reported in the literature.