A 2×2 phased-array transmitter designed for V-band communications has been implemented by using CMOS 0.18 m process. The circuit is based on a 30-GHz injection-locked oscillator (ILO) without using power amplifier. Combing a frequency doubler (FD) with the differential signal injection can generate a 60-GHz signal and perform a 360° phase shift with a harmonic suppression of 15 dBc. The power consumption of each channel in the transmitter is 65 mW from a 1.8 V supply. The measured output signal exhibits a self-oscillation frequency ranging from about 63.7 GHz to 65.9 GHz with an output power of -11 dBm. The transmitter demonstrates the maximum locking range up to 350 MHz under a fundamental injection. Due to the injection locking technique used in the circuit, the phase noise can be improved to -116 dBc/Hz at 1-MHz offset.