Based　on　the　Taiwan　Semiconductor　Manufactory　Company　(TSMC)＇s　0.35　μm　silicon　germanium　(SiGe)　process,　an　inductorless,　small　chip　area　SiGe　heterojunction　bipolar　transistor(HBT)　low-noise　amplifier　(LNA)　for　Ultra-wideband　(UWB)　application　was　designed.　The　input　impedance　matching　and　the　output　impedance　matching　of　the　LNA　are　both　achieved　by　using　the　resistance　feedback　structure　instead　of　the　LC　matching　network　structure　in　order　to　save　the　chip　area.　And　the　LNA　uses　the　Darlington-Cascode　structure　as　its　output　stage　to　improve　its　gain　and　linearity　because　the　structure　has　the　advantage　of　high　linearity　of　Cascode　and　the　advantage　of　high　gain　of　Darlington.　The　Darlington-Cascode　structure　was　constructed　based　on　the　analysis　of　the　linearity　and　3-dB　bandwidth　of　Cascode.　The　topology　and　the　chip　layout　of　the　LNA　were　designed,　with　its　area　being　only　0.046　mm2.　The　simulation　results　of　the　LNA　demonstrate　that　in　the　range　of　UWB,　the　gain　of　a　LNA　is　19.5~20　dB,　the　gain　flatness　is　±0.25　dB,　the　linearity　is　-5~-2　dBm,　with　the　satisfactory　input　impedance　matching　and　the　output　impedance　matching.　The　LNA　is　unconditionally　stable　in　the　whole　band.