A　dual-band　variable　gain　amplifier　operating　at　0.9　GHz　and　2.4　GHz　was　designed　based　on　high　performance　RF　SiGe　HBT　for　large　amount　of　signals　transmission　and　analysis.　Current　steering　was　adopted　in　gain-control　circuit　to　get　variable　trans-conductance　and　then　variable　gain.　Emitter　degeneration　and　current　reuse　were　considered　in　amplifying　stage　for　low　noise　figure　and　low　power　dissipation　respectively.　A　single-path　circuit　resonating　at　two　frequency　points　simultaneously　was　designed　for　input　impedance　matching.　PCB　layout　parasitic　effects,　especially　the　via　parasitic　inductor,　were　analyzed　theoretically　and　experimentally　and　accounted　for　using　electro-magnetic　(EM)　simulation.　The　measurement　results　show　that　a　dynamic　gain　control　of　26　dB/16　dB　in　a　control　voltage　range　of　0.0-1.4　V　has　been　achieved　at　0.9/2.4　GHz　respectively.　Both　S-11　and　S-22　are　below　than　-10　dB　in　all　the　control　voltage　range.　Noise　figures　at　both　0.9　GHz　and　2.4　GHz　are　lower　than　5　dB.　Total　power　dissipation　of　the　dual-band　VGA　is　about　16.5　mW　at　3　V　supply.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.