A 52–57 GHz 6-Bit Phase Shifter With Hybrid of Passive and Active Structures

It is very hard to realize a 6-bit resolution millimeter-wave phase shifter whether by passive structure or by active structure. A 52-57 GHz 6-bit phase shifter with hybrid of passive and active structures is proposed. The switched LC phase shifter is adopted for the passive structure because of its compact size, and the vector-sum phase shifter is chosen for the active structure in the 6-bit phase shifter. The proposed 6-bit phase shifter uses the passive structure to realize 5.625° and 11.25° phase shifts and uses the active structure to realize the N × 22.5° phase shifts. Implemented in Taiwan Semiconductor Manufacturing Company 40-nm CMOS technology, the 6-bit phase shifter has a RMS error <;3.76° and a RMS gain error <;2.23 dB at 52-57 GHz. The proposed 6-bit millimeter-wave phase shifter achieves a high phase resolution with a compact size. The core die occupies an area of 500 μm × 300 μm and consumes about 13 mA from a 1.1-V supply.