A DC-50GHz 6-Bit Passive Attenuator with Dual-Path Capacitor Compensation Bandwidth Extension Technique for 5G Millimeter-Wave Applications

This paper presents a 6-bit wideband passive attenuator with high attenuation accuracy and low phase error in 40-nm CMOS technology. To address the limitations of conventional capacitor compensation π-type structure in 5G millimeter-wave (mm-wave) multi-band applications, a novel dual-path capacitor compensation (DPCC) technique is proposed to minimize amplitude error at high frequencies and expand its operating bandwidth. From DC to 50 GHz, the attenuator demonstrates a 31.5-dB attenuation range with a 0.5-dB step size and a 4.3–8.5 dB insertion loss (IL). The RMS amplitude and phase errors are below 0.27 dB and 1.3° respectively. In the frequency range of 24 GHz to 44 GHz, the RMS amplitude and phase errors are further reduced to below 0.16 dB and 1.29°, demonstrating excellent amplitude and phase performance for 5G mm-wave applications. The attenuator occupies 0.13 mm² core area with negligible power consumption.