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 <inline-formula> <tex-math notation="LaTeX">${R}$ </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> 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.