Gain and phase-matched low-noise TWT amplifiers

This paper will be presented in two parts. The first presents the latest advances in precision gain and phase-matched amplifiers. A set of three C-Band low-noise traveling-wave amplifiers has been gain and phase matched to stringent combination of electrical and environmental speeifications for a new mono-pulse radar system. No previous C-Band amplifiers of any kind have attained such a low noise figure (about 5 db at room temperature) with a power output of 20 milliwatts. In addition, these units are required to remain extremely gain and phase stable over a wide temperature range, to be gain and phase matched, and meet numerous other specifications sueh as low VSWR, fine grain, spurious PM, tube-to-tube interaction, and low AM-PM conversion. These results, which are important for designers of sensitive mono-pulse and phase array radar receivers with wide dynamic range, are a significant advance with respect to those reported by the author two years ago. At that time, the best gain stability achivable over a wide temperature range was ±1 db. The best phase stability consistently achieved was ±15°.