Abstract: Towarding the demand of high performance low noise amplifier devices for microwave and millimeter wave low noise amplifiers, low noise technology based on 0. 15μm gate length GaAs PHEMT is developed . In the process, excellent ohmic characteristic is realized by adopting composite cap ohmic contact, low gate parasitic capacitance is realized by adopting a gate structure with dielectric void and high breakdown voltage is realized by adopting double trench structure. A high performance Ku band low noise amplifier is realized based on it. The LNA circuit achieved excellent performance in the whole Ku band(14 ~18 GHz) ,NF<1. 3 dB,gain>17 dB. The circuit consumes 250 mW with 5V power supply,the chip area is 2 mm ×1. 6 mm. This high performance Ku band low noise amplifier is ideal for high SNR applications such as satellite communication and so on.