60GHz low-loss compact phase shifters using a transformer-based hybrid in 65nm CMOS

Two compact, low-loss, passive reflective type 60GHz phase shifters are presented in a standard 65nm CMOS technology. The designs use lumped-element baluns to implement the hybrid with an insertion loss better than 0.7dB. The first architecture achieves 180 degrees phase shift with an average loss of 6.6dB and area of 0.031mm². The second phase shifter demonstrates the best reported average loss of 4.5dB with an area of 0.048mm² while having ~150 degrees of phase shift. Both designs provide more than 10GHz of bandwidth. These are the smallest reported 60GHz phase shifters in silicon.