A 48 GHz 6-bit LO-path phase shifter in 40-nm CMOS for 60 GHz applications

Abstract

This paper presents a 48 GHz high resolution LO-path phase shifter implemented in 40-nm low-power CMOS technology. The full 360° phase shift tuning is implemented by a switched capacitor loaded tunable transmission line for fine tuning, in combination with a selection of one out of the N×45° phase steps available from the frequency divider-by-4 for coarse tuning. The measured phase shift resolution is 5.4° between 44 GHz and 54 GHz, which offers about 6-bit resolution. The chip area of the core circuitry is 550μm×260μm, and the total current consumption is 14.1 mA from a 1.2 V supply voltage.