A 38-GHz 32-Element Phased-Array Transmitter Based on Scalable 8-Element Phased-Array Modules for 5G MMW Data Links

This paper presents a 38-GHz 32-element phased-array transmitter for 5G MMW communication. An 8-element phased-array Tx module with 2 GHz IF/5 GHz LO feeds is implemented as a unit cell, and four pieces of the module are stacked to realize an 8×4 brick array. The 38 GHz measurement of the 32-element Tx array shows 41.8 dBm EIRP at OP1dB with -41.8 dBc IMRR and -35 dBc ×8 LORR. The EIRPs at OP1dB in beam scanning around ±60。azimuth/±30。elevation planes are 41.8-37.8 dBm. The Tx is utilized for data links with a horn antenna module in 35 meters that demonstrates 256 QAM/100M-BR with -33.1 dB EVM. Data links of the Tx with a 4-element phased-array receiver demonstrates 64 QAM/200M-BR with -26.4 dB EVM in 6 meters. The scalable Tx module shows potential for 5G sub-6 GHz/MMW coexistent applications and can be extended as a massive-element phased-array using simple and low-cost stacked methods.