A Novel 5-30GHz Voltage Controlled Variable Attenuator with High Linearity in a Low Cost SMD Compact Package

The design and performance of a compact packaged 5-30GHz variable attenuator are reported in this paper. Using a standard 4-inch 0.7mum GaAs power MESFET technology with BCB coating and backside metallization, these shunt-type packaged attenuator exhibits more than 25dB dynamic range, with a nominal insertion loss from 3 to 6dB over the 5-30GHz frequency band. Using multi-gates FETs and biasing voltage sequential control, input power compression of more than 25 to 30dBm is achieved. To allow a significant cost reduction for RF module assembly, this voltage attenuator MMIC is housed in a standard 16L-QFN3times3 SMD molded package. To the author's knowledge, these results show the highest linearity reported up to now for a voltage variable attenuator in a SMD package