A monolithic DC-1.6 GHz digital attenuator

A 5-bit attenuator with integral TTL-compatible switch drivers is described. The unit has a 15.5 dB attenuation range in 0.5 dB increments, 3 dB insertion loss, operating frequency range from DC to 1.6 GHz, and 1.4:1 input/output VSWR (voltage standing-wave ratio) over that frequency range. The unit uses GaAs MESFET integrated circuit technology. The performance is typified by its integral and differential linearity (<0.25 dB at 1.6 GHz and <0.1 dB below 1.6 GHz) and 15-ns RF switching time. The power performance is typified by its <250-mW power consumption and 20-dBm maximum RF input power level.<>