A bidirectional TX/RX four element phased-array at 60GHz with RF-IF conversion block in 90nm CMOS process

A 60 GHz 4 element bidirectional phased-array TX/RX chip with a 2 bit phase shifter and IF converter to/from 12 GHz, using 90 nm CMOS process, is described. The array features 7 dB gain, measured noise figure (NF) of 9 dB, IP1dB of -19 dbm for RX, and output Psat of +3.5 dBm for TX , drawing 60 mA from a 1.3-V supply. The RMS amplitude and phase error of the phase shifter is 0.7 dB and 2deg max respectively from 57 to 66 GHz. This new architecture together with the compact layout decreases chip size to about half compared to a separate TX and RX design. The use of passive phase shifters and combiners reduce the current consumption. Total die area is 1.6times1 mm
²
with half of the area being the IF converter block. First pass success was achieved by the closed ground environment design methodology of the passive structures and by proper layout. To our knowledge, this the first report on a bidirectional 60 GHz array, with the lowest reported chip power consumption and size.