B y pass low-noise amplifier (LNA) can be used in the base station receiver to improve the d y namic range. It is difficult to achieve both ultra low noise at LNA mode and maintain good linearit y at b y pass mode simultaneousl y . In this work, we present the best performance b y pass LNA with 0.5 dB of noise figure (NF), 20 dB of gain at 1.95 GHz and high OIP3 of 35 dBm for both LNA and b y pass mode. Fabricated in 0.25um GaAs EID pHEMT process, the LNA is based on enhancement mode pHEMT cascode topolog y and the switches are designed with the depletion mode pHEMT. Index Terms -B y pass LNA, ultra low noise, switches, high linearit y , GaAs EID-pHEMT. .(J.15 ·0.10 ·0.05 0.00 0.05 0.10 0.15 Delta _ Vp Delta _ Vp Fig. 7. Simulated OIP3 and NF vs. Delta_ Vp