Harmonic-Multiplying Gryo-Amplifiers. The Phigtron has been studied both theoretically and experimentally to demonstrate the performance capability of harmonic gyro-amplifiers and investigate the nonlinear electronic processes which are the basis for these devices. The key issues are to what extent frequency multiplication and cyclotron harmonic operation may degrade or possibly improve amplifi...

Spaceborne precipitation radars are powerful tools used to acquire adequate and highquality precipitation estimates with high spatial resolution for a variety of applications in hydrological research. The Global Precipitation Measurement (GPM) mission, which deployed the first spaceborne Kaand Ku-dual frequency radar (DPR), was launched in February 2014 as the upgraded successor of the Tropical...

A new non-linear method for design and analysis of solid state power amplifiers is presented and applied to an aluminum gallium nitride, gallium nitride (AlGaN-GaN) high electron-mobility transistor (HEMTs) on silicon-carbide (SiC) substrate for Ku band (12.4 13.6 GHz) applications. With combining output power of 8 transistors, maximum output power of 46.3 dBm (42.6 W), PAE of 43% and linear ga...

Abstract. Owing to differing and complex snow geophysical properties, radar waves of different wavelengths undergo variable penetration through snow-covered sea ice. However, the mechanisms influencing altimeter backscatter from ice, especially at Ka- Ku-band frequencies, impact on scattering horizon or “track point” (i.e. layer depth detected by re-tracker) are not well understood. In this stu...

Abstract. Cloud radars are widely used in observing clouds and precipitation. However, the raw data products of cloud usually affected by multiple factors, which may lead to misinterpretation precipitation processes. In this study, we present a Doppler-spectra-based processing framework improve quality multi-mode pulse-compressed Ka–Ku radar system. Firstly, non-meteorological signal close grou...

The Khan Academy platform enables powerful on-line courses in which students can watch videos, solve exercises, or earn badges. This platform provides an advanced learning analytics module with useful visualizations. Nevertheless, it can be improved. In this paper, we describe ALAS-KA, which provides an extension of the learning analytics support for the Khan Academy platform. We herein present...