A 1–18 GHz Single Supply 5-Bit Low Power Consumption MMIC Digital Attenuator

A broad band 1 to 18 GHz 5-bit Monolithic Microwave Integrated Circuit (MMIC) digital attenuator presented in this paper. The presented attenuator has high accuracy, low insertion loss, low insertion phase shift and low power consumption and is realized using enhancement/depletion (E/D) mode GaAs pseudomorphic high electron-mobility transistor (pHEMT) process. Attenuator fabricated in 0.25um GaAs PHEMT process. The digital attenuator achieves a 15.5dB dynamic attenuation range stepped by 0.5dB with better than 5.7dB insertion loss over the band and fewer than +/-0.5dB major state attenuation error in the band 8-18GHz. Major state linear phase variation less than 20deg realized in die size of 1.46x1.6 sq.mm.