The MDU-091A broadband analog front-end card in the METER™ series of PXI measuring instruments is a front-end module for broadband vector source (VSG)/broadband vector signal analyzer (VST). It has the capabilities of circuit protection and performance expansion, and realizes functions such as gain control and analog filtering. It can be used in combination with MET®'s MVT/MVG/MSA series measurement units and is effectively applied to test systems in various complex scenarios.