A 22–24 GHz 4-Element CMOS Phased Array With On-Chip Coupling Characterization

This paper presents a 22-24 GHz CMOS 4-element phased array based on the all-RF architecture with very low power consumption and chip area. The measured array performance, done at the system level at 22-24 GHz, shows an input and output match of <-13 dB, 9-12 dB gain, 7.5-8.0 dB NF, an IIP3 of -9.5 to -12.5 dBm, and a 4-bit phase control with an rms gain and phase error of <1.2 dB and <6deg, respectively (<0.5 dB and <3deg at 23.5-24.5 GHz). The chip consumes 76.5 mA from a 1.5 V supply and is 3 mm² in area. Extensive coupling measurements show that the dominant on-chip coupling components result in system-level gain and phase errors which are proportional to the LNA gain. To our knowledge, this is the first analysis of on-chip coupling effects on phased array performance, and the first demonstration of an all-RF mm-wave CMOS phased array with full amplitude and phase control on each element. The application areas are in high data-rate communications and automotive radars.