Design of a Wideband Digital Attenuator MMIC Over 1 to 10 GHz

This paper on digital attenuator presents the design and development of a wideband MMIC over frequency range of 1-10 GHz, fabricated using 0.25 um GaAs p-HEMT process. The topology adapted is modified $\pi$- and T-type attenuator structures to enhance frequency of operation and to improve the performance, regarding insertion loss and the variation of insertion phase. The total attenuation of DA is of 15.5 dB and attenuation step of 0.5 dB. This attenuator realized on the footprint of 3.5 mm $\times 2$ mm, and the measured worst case rms amplitude errors are 0.4 dB and phase errors are 3.5° over a wide band of 1-10 GHz, evaluated over 5 chips and shows excellent performance validation against specifications.