Abstract: An L-band monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) used in satellite microwave receiver was developed with 0.25μm GaAs pseudomorphic high electron mobility transistor (pHEMT) technology. The current reuse topology structure was used to achieve lower current and the precious satellite power resource was saved. The two-stage negative feedback was applied to increase stability and gain flatness, and then satellite communication quality was improved. The constant current source bias stabilized the working conditions where current was slightly influenced by the processes. The test results show that the working current is below 35mA, from 0.9GHz to 1.8GHz, the gain is higher than 33dB with gain flatness less than 0.5dB, the noise figure is below 0.6dB, and the size of the LNA chip is 2.0mm×1.3mm. The circuit can meet the requirement of high performance and miniaturization in space application.

Key words: low noise amplifier, monolithic microwave integrated circuit, negative feedback, wideband, noise figure, receiver