This work proposes a bselection filter (BSF) for a fully integrated ultra-wideb(UWB) 3.1-10.6 GHz/Ku b11.8-14.8 GHz dual-blow-noise amplifier (LNA) in 0.13 μm CMOS technology. Detailed analysis design criteria of the proposed BSF widebLNA are given. The operating frequency bcan be selected by the transistor Mn between its off on states. The BSF is designed, analysed fabricated in a 0.18 μm CMOS process to verify its feasibility. The BSF has a minimum insertion loss of 0.7/2.9 dB for a low-pass high-pass filter, an input-referred IP3 (IIP3) exceeding 20/33 dBm in the off on states. The measured performance of the switched LNA in UWB bachieves a maximum power gain of 12.3 dB a 1-dB bandwidth of 2-10.5 GHz, a minimum noise figure (NF) of 4.9 dB an IIP3 of -16.7 dBm. In Ku band, the measured performance are a maximum power gain of 10.7 dB with a 1-dB bandwidth of 11.5-13.5 GHz, a minimum NF of 5.7 dB an IIP3 of -16.1 dBm. The dual-bLNA consumes a DC dissipation power of 14.3 mW from a 1.1 V supply voltage. The chip area, excluding pads, is only 0.35 mm2.