A K-/Ka-band distributed attenuator in a 28-nm CMOS process is presented for a phased array. The proposed voltage-controlled distributed attenuator is designed using nonuniform varistors for a wide attenuation range with a compact size. An attenuation range of 25 dB was achieved with only three sections, which are 90° apart. The phase imbalance of the proposed attenuator is minimized using an artificial quarter-wave transmission line with series-connected varistors. The measured insertion loss of the proposed attenuator is 1.6–2.5 dB from 20 to 36 GHz. The insertion phase imbalance is less than 10° within the same bandwidth. The input 1-dB compression point is 10.6 dBm (defined as the 1-dB drop in the maximum attenuation range) at 28 GHz. The total chip size, including pads, is 0.77 ${\times }$ 0.42 mm ² . The proposed attenuator has the highest attenuation range relative to the chip area compared with previously distributed attenuators.

中文翻译：

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具有宽衰减范围和低相位不平衡的20–36 GHz电压控制模拟分布式衰减器

提出了一种采用28 nm CMOS工艺的K / Ka波段分布式衰减器，用于相控阵。拟议的压控分布式衰减器是使用非均匀变阻器设计的，具有宽广的衰减范围和紧凑的尺寸。仅三个相隔90°的部分就实现了25 dB的衰减范围。使用带有串联压敏电阻的人造四分之一波长传输线，可以最大程度地减少所提出的衰减器的相位不平衡。在20至36 GHz范围内，建议的衰减器的实测插入损耗为1.6–2.5 dB。在相同带宽内，插入相位不平衡度小于10°。输入的1-dB压缩点在28 GHz时为10.6 dBm（定义为最大衰减范围内的1-dB下降）。包括焊盘在内的总芯片尺寸为0.77 $ {\ times} $ 0.42毫米 ² 。与先前分布的衰减器相比，所提出的衰减器相对于芯片面积具有最高的衰减范围。