A DC to 70GHz Distributed Low Noise and Medium Power Amplifier

This paper presents a DC to 70 GHz distributed amplifier (DA) for instruments applications. The DA is designed and fabricated based on a 0.1 um GaAs pHEMT process. A distributed structure of 7-stage cascode topology was utilized to improve bandwidth. The DA chip was tested at probe station, and the test results show that, the amplifier exhibits 11 dB of small gain and the gain flatness is lower than ±1 dB. The average noise figure (NF) is 5.5 dB in the frequency range over 70 GHz, and 1 dB compression output power of the DA is better than 10 dBm with power consumption less than 340 mW. The DA has been adopted widespread in microwave test instruments.