A 60 GHz receiver front-end with PLL based phase controlled LO generation for phased-arrays

This paper presents a fully integrated 60 GHz front-end for phased array receivers. For the first time in the literature a phase controlled phased locked loop (PC-PLL) is used for beamforming at 60 GHz. The front-end performs a two stage frequency down-conversion, first from 60 GHz to 20 GHz, then from 20 GHz to quadrature baseband. Both the local oscillator signals at 20 GHz and 40 GHz are generated by a single 20 GHz QVCO without any frequency multipliers. The measured results show an input return loss better than -10 dB between 57.5 GHz and 60.8 GHz, 15 dB voltage gain, and 9 dB noise figure. Two-tone measurements show a -12.5 dBm IIP₃, 29 dBm IIP₂, and -24 dBm ICP_1dB. The phase control of the PLL has a resolution of 3.2 degrees and the control range exceeds 360 degrees. The chip consumes 80 mA from a 1.2 V supply, and measures 1400 μm × 660 μm (900 μm × 500 μm excl. pads) incl. LNA, mixers, and PC-PLL in a 90 nm RF CMOS process.