Optimization of radiometric circuitry in developing high-precision polarimeters and fast-response spectrum analyzers

摘要

The paper suggests new circuitry solutions which offer an increased brightness-temperature and frequency resolution in radiometric devices. The issues of microwave identification of cloud phase composition require the development of polarimeters - polarization radiometers - with simultaneous real-time measurement of vertical, horizontal, and difference polarizations. The main requirements imposed on such devices include high sensitivity, stability, wide dynamic range, noise immunity, and optional self-contained power supply. The task of spectrally monitoring solar activity in the microwave range calls for spectrometers with very small values of integrating constant. The proposed engineering solutions allow the polarimeter sensitivity to reach 0.05 K, which is approximately 3-4 times higher than with previously available polarimeters. The designed heliospectrograph offers a 4-times faster response. The implemented technique of asymmetrically separating the modulation signal offers a 17% increase in sensitivity compared to 'classical' techniques.