A Frequency Tunable 360° Analog CMOS Phase Shifter With an Adjustable Amplitude

This brief presents a new vector sum phase shifter topology utilizing a current mode R-C poly phase filter along with several current steering variable gain amplifiers. The phase shifter performs all the tasks of vector generation, gain control, and vector summation in a single block (phase shifter core) to save power and area. The phase shifter core provides 360° of continuous phase tuning with an adjustable amplitude while consuming only 0.063 mm2 of on-chip area. The phase shifter can generate a signal with a tunable phase and magnitude in a phased array, thereby providing a better control over the beamwidth and sidelobe levels. The circuit is frequency reconfigurable, and its center frequency can be tuned within 26-28 GHz with an instantaneous bandwidth of 3 GHz. The phase shifter, fabricated in 130-nm CMOS technology, occupies an area of 0.284 mm2 (excluding the pads) and consumes 27 mW of power. The phase shifter's RMS phase and gain errors for 64 measured phase states are less than 2.6° and 0.31 dB, respectively, within the 3-dB bandwidth. The measured IP1dB and IIP3 are larger than -9.8 and 0 dBm, respectively. This phase shifter is a good candidate for automotive radar as well as 5G applications.