Book excerpt: Other than improving the linearity of the LNA, programmable band-select RF front-end circuit is another approach to enhance the robustness of the UWB transceiver to strong narrowband interferers that is proposed in this work. The idea is to grant the LNA the ability to switch pass band, such that the transceiver can detect and avoid the strong narrowband interferers, which greatly improve the ability of UWB RF front-end to survive strong narrowband interferers. Two 3-10 GHz band-select UWB LNAs with active balun, one configurable between narrowband (3-5 GHz) and wideband (3-10 GHz) mode and the other configurable between low band (3-5 GHz) and high band (6-10 GHz) mode, are designed and fabricated in IBM 0.13 um CMOS process to demonstrate the proposed concept.