A new tunable all-pass phase shifter architecture based on current mirror, with low complexity and power consumption is proposed in 0.18um CMOS, after a brief introduction on phase shifter applications. In the new current-mode approach the cut-off frequency of transistor is the operational limit of the proposed phase-shifter architecture and power consumption for this design is 80 microwatts. Simulations are carried out in HSpice and cover a frequency range from 1MHz to about 50GHz.