M. Yu. Kulikov

Ground-based microwave spectroradiometer for thermal sounding of the troposphere

The laboratory model of a mobile solid-state uncooled microwave spectroradiometer, operating in the frequency range of 50 to 55 GHz is described. It is designed for remote passive monitoring of the tropospheric temperature. The spectroradiometer consists of a heterodyne receiver with a low noise amplifier at input and 8-channel spectrum analyzer. To ensure the internal calibration of the intensity of the received atmospheric radio emission using the built-in unit type modulator-calibrator based on GaAs diodes with the Schottky barrier. The antenna system of the spectroradiometer consists of a teflon enlightened lens and conical corrugated horn. The device is equipped with an automated control system process measurement, calibration, and data pre-processing.

Measuring the parameters of solid and liquid dielectrics at microwave frequencies with the use of microstrip photonic structures

Features of interaction of microwave electromagnetic radiation with one-dimensional photonic crystals made on the basis of microstrip transmission lines with a variable substrate permittivity and variable width of the upper strip conductor are investigated. A method for determining the parameters of solid and liquid dielectrics from the measured frequency dependences of the coefficient of transmission of electromagnetic radiation interacting with the microstrip photonic structure, in which the samples under investigation act as irregularities, is theoretically substantiated and experimentally implemented. The results of measuring the complex permittivity of a number of liquid dielectrics are presented.

Automated microwave radiometer for measuring the atmospheric ozone emission line

The work presents the results of upgrading of microwave spectroradiometer for ground-based remote sensing of Earth’s ozone layer improving essentially the noise temperature (up to value less 1500 K). For this, the low-noise high frequency amplifier was set up in front of the receiver and temperature control of the instrument was changed for stable work of the amplifier.

A calibration system for microwave radiometers based on a modulator–calibrator

A system for automatic internal calibration of millimeter-range radiometers is described. This system is based on an electrically controlled modulator–calibrator, which is a compact solid-state device that combines the functions of a modulator and a source of stable noise calibration signals. Stability of the calibration levels is provided by thermostatting the modulator–calibrator case and stabilization of the control currents. The calibration and data-collection process is governed by software using a special digital module and a personal computer.