This letter presents a compact Ka-band 4-bit switch-type phase shifter with low group delay deviation (GDD) using 28-nm CMOS technology. A magnetically coupled all-pass network (APN) configuration is employed to achieve both equal and flat group delay characteristics versus frequency at each phase state. The measured rms phase error is 1.2°, and the gain error is 1.1 dB at 33 GHz. The average measured insertion loss is 12.8 dB at 33 GHz, and the input and output return losses are both lower than -10 dB from 29 to 37 GHz. The fabricated phase shifter has a compact size of 0.08 mm2 excluding pads, low GDD of ±4 ps, and rms group delay error of <; 2.2 ps between 16 phase states from 29 to 37 GHz. The proposed Ka-band phase shifter has the lowest GDD per bandwidth (GDD/BW) compared with other reported passive phase shifters.

中文翻译：

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具有低群延迟偏差的紧凑型 Ka 波段 4 位移相器


这封信介绍了一种采用 28 nm CMOS 技术、具有低群延迟偏差 (GDD) 的紧凑型 Ka 波段 4 位开关型移相器。采用磁耦合全通网络 (APN) 配置来实现每个相位状态下相同且平坦的群延迟特性与频率的关系。 33 GHz 时测得的均方根相位误差为 1.2°，增益误差为 1.1 dB。 33 GHz 时测得的平均插入损耗为 12.8 dB，29 至 37 GHz 时输入和输出回波损耗均低于 -10 dB。所制造的移相器具有 0.08 mm2（不包括焊盘）的紧凑尺寸、±4 ps 的低 GDD 和 < 的 rms 群延迟误差； 29 至 37 GHz 16 个相位状态之间为 2.2 ps。与其他报道的无源移相器相比，所提出的 Ka 波段移相器具有最低的单位带宽 GDD (GDD/BW)。