A 0.1–4.5 GHz MMIC Controlled Digital Step Attenuator Based on SiGe

Abstract

Circuit schematics and a technique for designing controlled microwave digital step attenuators (DSAs) are described. The measurement results for the developed 0.1–4.5 GHz ET1000 microwave monolithic integrated circuit (MMIC) DSA with a parallel and serial control driver are presented. The MMIC DSA is fabricated based on the 0.25-μm SiGe BiCMOS technology. The DSA bitness is 5 bit, the attenuation range is 30 dB with a 1-dB step, and the input power at the 1 dB gain compression is at least 14 dBm. The MMIC has such advantages as a wide bandwidth, good input and output matching, a low phase error, and a small consumption current. The MMIC DSA can be used in unpackaged and packaged variants as in wideband measuring equipment as in receivers and transceivers for various applications.