A Cascaded Salty Water Attenuator

A salty water attenuator based on $\Pi$-type resistance attenuation network is proposed. It is composed of a metallic tapered parallel transmission line, a 3-D-printed container, and the salty water. By using cascaded method and the fluidity of salty water loading, the proposed design achieves a wider frequency working range, a more compact size, a lager attenuation and a better heat dissipation. Both the simulations and measurements have been conducted to verify the attenuator performance. The $\Pi$-type liquid attenuator has an attenuation of -30 dB with attenuation flatness of ± 3.2 dB operating between DC and 2 GHz (the reflection coefficient is less than -10 dB across the band).