The work presented describes the characteristics of single stage and severed high-efficiency, high-power traveling-wave tube amplifiers operating in X band at 8.76 GHz. Average amplified output powers of 210 MW have been achieved at 24% efficiency. At high output power levels ( > 100 MW) sidebands develop increasing the average radiated power to over 400 MW with a microwave conversion efficienc...

This paper presents the progress of monolithic technology for microwave application, focusing on gallium nitride technology advances in the realization of integrated power amplifiers. Three design examples, developed for microwave backhaul radios, are shown. The first design is a 7 GHz Doherty developed with a research foundry, while the second and the third are a 7 GHz Doherty and a 7–15 GHz d...

We present a new theoretical framework to analyze microwave amplifiers based on the dc SQUID. Our analysis applies input-output theory generalized for Josephson junction devices biased in the running state. Using this approach, we express the high-frequency dynamics of the SQUID as a scattering between the participatingmodes. This enables us to elucidate the inherently nonreciprocal nature of g...

This thesis addresses integrated circuit component, packaging, and microwave design for both AC and DC Josephson voltage standard (JVS) systems. The components developed in this work combine techniques from both the distributed and lumped-element microwave design in the frequency range 0–40 GHz. The National Institute of Standards and Technology (NIST) JVS systems rely on 10 000 to 300 000 micr...