Broadband compact InGaAs pin 5-bit digital attenuator using πtype resistive network

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.