A 2-18 GHz 6-Bit GaAs Positive Voltage Driven Digitally Controlled Attenuator for Phased Array

In this paper, an ultra-wideband 6-bit digitally controlled attenuator MMIC for the active phased array that integrates positive voltage digital driving circuits was developed, utilizing GaAs enhanced and depletion mode p-HEMT process. The attenuator design operates in an ultra-wide bandwidth of 2-18 GHz, with a dynamic attenuation range of 0.5-31.5 dB and an attenuation accuracy of less than 0.9 dB over the entire frequency band. The integrated DCFL (direct coupling field effect transistor logic) inverter circuit on the chip enables direct control of the attenuator with a positive voltage while occupying a chip area of only 2.7 mm ² .