Low-loss, high-power, broadband GaAs MMIC multi-bit digital attenuators with on-chip TTL drivers

The design and performance of low-loss, high-power, multi-bit GaAs MMIC digital attenuators are presented. A four-bit digital attenuator with 1 dB steps, operating from DC to 6 GHz, has a maximum 2 dB insertion loss at 6 GHz and 85 degrees C. A two-bit digital attenuator covering DC to 2 GHz in 16 dB steps has 0.9 dB insertion loss at 2 GHz. The chip size for both of these attenuators is 48*48 mils including on-chip digital decoders. The attenuators are capable of handling greater than 23 dBm of input power at any attenuation level, and the return loss across the band is better than 18 dB.<>