A　dual-band　low　noise　amplifier　(DBLNA),　which　can　operate　at　2.4　GHz　and　5.8　GHz,　is　designed　and　realized.　Infineon　BFP740　SiGe　HBTs　are　chose　as　active　device,　the　cascode　structure　with　high　isolation　and　wider　bandwidth　is　selected　as　gain　circuit　stage,　whose　bias　current　is　selected　to　obtain　minimum　noise　figure.　In　order　to　cope　with　the　error　of　board　technology　and　the　PCB　transmission　loss,　an　additional　stage　is　added　into　the　cascode　amplifier　stage,　both　the　peaking　inductor　and　the　RC　circuit　are　utilized　to　compensate　the　decrease　of　high-frequency　gain.　A　voltage　divider　circuit　by　resistor　is　employed　to　provide　bias　current,　and　the　bias　point　is　determined　by　scanning　IB-NF.　For　the　sake　of　miniaturization　and　adjustability,　the　π-type　micro-strip　line　is　used　to　achieve　input/output　matching.　The　combination　of　the　electromagnetic　simulation　and　the　schematic　diagram　simulation,　so-called　co-simulation,　is　used　to　guarantee　the　simulation　results　are　close　to　actual　case.　Finally　the　board-level　layout　is　designed　and　the　DBLNA　PCB　is　fabricated　and　measured.　©　2014　WIT　Press.