A Compact, Supply-V oltage Scalable 45–66 GHz Baseband-Combining CMOS Phased-Array Receiver

Abstract

This paper presents a four-element phased-array re- ceiver which achieves 38% frac tional bandwidth around 55 GHz. Baseband phase-shifting is employed to eliminate wideband phase-shifters, power dividers, a nd quadrature splitters operating at millimeter-wave frequencies. Antenna weighting and combining are accomplished using a highly digital Cartesian phase-shifter and current summation, respectively. Transformer-coupling techniques are introduced in the LNA to simultaneo usly achieve wide bandwidth, reduced noise figure, gain boosting and neutral- ization. Cascode-free and folded topologies are used throughout to enable operation from a scalable supply volta ge. To overcome challenges associated with wideband LO distribution, the LO network employs multiconductor transmission lines to distribute four-phase LO signals. The LO distributi on network is absorbed into the LO buffers and terminated by distributed LC loads near the I/Q mixers in each phased-array element. The phased-array receiver is fabricated in a 45 nm SOI CMO Sp r o c e s sa n da c h i e v e s 26.2 dB (20.2 dB) of element gain over 21 GHz (19 GHz) of 3 dB bandwidth with 5.5 dB/9.8 dB (7.7 dB/12 dB) minimum/maximum NF while dissipating 30 mW/element ( 14 mW/element) from a 1.1 V (0.6 V) supply voltage. The worst case 1 dB (input) compression is 28 dBm at 1.1 V. A worst case coupling of 26 dB (45 dB) is measured between adj acent (nonadjacent) elements. The IF bandwidth is 1.2 GHz, limited by the wirebond and PCB