A 6-bit attenuator of 8–12 GHz with low phase variations in 0.13-um CMOS technology

A X-band monolithic attenuator (ATT) is presented in this paper, which is fabricated in commercial 0.13-um CMOS technology. A capacitive low pass filter is adopted to improve phase variations of large attenuation states. The results show that this 6-bit attenuator achieves less than 0.35 dB of root mean square (rms) amplitude errors at 8 GHz-12 GHz within ±3° of phase variations. The core cell chip size is 450×370 um
²
excluding pads.