A Compact 28 GHz Bi-Directional Power-Combined Antenna Interface in WLCSP for 5G and B5G Transceivers

This letter introduces an area-efficient 28-GHz CMOS antenna interface with wafer-level chip-scale packaging (WLCSP) for 5G and B5G transceivers. The power-combining technique is adopted in this work to improve the TX-mode power delivery. To maintain a compact footprint for phased-array transceivers, the neutralized bi-directional architecture is also employed. A complete implementation of power amplifier (PA), LNA, and TRX switch is integrated within a core area of 0.33 mm2. In measurement, the saturated power of 18.1 and 16.8 dBm are realized in TX mode at 28 GHz by the power-combined PA with and without WLCSP, respectively. 24% peak PAE is also achieved after packaging. A data rate of 18 Gb/s is maintained by the PA with 10.6-dBm output power. In RX mode, the packaged NF is 6.8 dB. The power consumption is 205 mW in TX mode and 33 mW in RX mode.