A vector modulator based phase shifter is developed using 0.18um CMOS process at S-band frequency to be integrated into a conformal phased array antenna to recover the desired radiation pattern in the entire 360° range. The phase shifter has a variable gain amplifier integrated into the circuit in order to vary gain along with phase for precise control to correct the degraded radiation pattern due to the conformal shaping. The results show state-of-the-art performances including more than 7dB conversion gain with variable feature, a continuous phase rotation of 360° with steps as low as 11.25° and very low power consumption of 17mW, for the first time to the best of the authors’ knowledge. The chip size including all pads is 1.5mm X 0.75mm.