Key Circuit Building Blocks for 5G Millimeter-Wave Phased-Array Transceiver Front-End (Invited)

Key building blocks for 5G millimeter-wave (mm-Wave) phased-array transceiver including broadband high-efficiency power amplifier (PA), amplitude-invariant phase shifter and phase-invariant variable gain amplifier (VGA) are presented. Challenges remain for the design of these circuits operating at the 5G mm-Wave band. To address these challenges, techniques are proposed such as weakly-coupled inter-stage transformer for broadband PA design, triple-resonating load technique for 360
^°
amplitude-invariant phase shifter design and dynamic elements elimination for phase-invariant VGA design. They provide possible solutions to the design of 5G mm-Wave phased-array transceiver front-end.