This paper proposes a transmission-line based bidirectional reflection-type phase shifter for the 2.5 to 3.2GHz frequency band. Open and short reflective loads are used to double the available phase shift and reduce insertion loss. The transmission line is implemented using inductors and MOS switches in a 65nm RF CMOS process. This work achieves a total phase shift of 180degree with phase resolution of 22.5degree at 2.85GHz and rms error of 1.2. The insertion loss of the phase shifter is 5.7dB and the loss variation is less than 0.3dB.