A broadband compact InGaAs pin 5-bit digital attenuator using a π-type resistive network is demonstrated. The proposed 5-bit digital attenuator is composed of π-type resistive networks for good input/output matching and accurate attenuation characteristics. The fabricated attenuator MMIC has good performance characteristics, such as an insertion loss less than 11.5 dB and a small RMS amplitude error of 2.3 dB at the broadband frequency range of 7–40 GHz. In addition, the overall chip size, which is significantly reduced by using the developed multilayer structure, is only 1.59×0.84 mm2.